Water | Chemistry | Visionlearning

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In fact, water’s chemistry is so complex and important that scientists today are still striving to understand all the feats this simple substance can perform."> <meta name="keywords" content="water, polarity, hydrogen bonds, surface tension, adhesion, cohesion"> <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no"> <meta name="msvalidate.01" content="D8E20F39AD48052260032E56DE409970"> <script type="application/ld+json"> { "@context": "http://schema.org/", "@type": "Article", "mainEntityOfPage": { "@type": "WebPage", "@id": "https://visionlearning.com/en/library/chemistry/1/water/267" }, "name": "Water", "headline": "Water: Properties and behavior", "author": [ { "@type": "Person", "name": "Robin Marks, M.A." } , { "@type": "Person", "name": "Anthony Carpi, Ph.D." }], "datePublished": "2018-02-25 17:17:58", "dateModified": "2017-02-12T08:30:00+05:00", "image": { "@type": "ImageObject", "url": "/img/library/moduleImages/featured_image_267-23061209064844.jpg", "width": 696, "height": 464 }, "publisher": { "@type": "Organization", "name": "Visionlearning, Inc.", "logo": { "@type": "ImageObject", "url": "http://visionlearning.com/images/logo.png", "width": 278, "height": 60 } }, "description": "Water is a truly unusual and important substance. The unique chemical properties of water that give rise to surface tension, capillary action, and the low density of ice play vital roles in life as we know it. Floating ice protects aquatic organisms and keeps them from being frozen in the winter. Capillary action keeps plants alive. Surface tension allows lily pads to stay on the surface of a lake. In fact, water’s chemistry is so complex and important that scientists today are still striving to understand all the feats this simple substance can perform.", "keywords": "water, polarity, hydrogen bonds, surface tension, adhesion, cohesion", "inLanguage": { "@type": "Language", "name": "English", "alternateName": "en" }, "copyrightHolder": { "@type": "Organization", "name": "Visionlearning, Inc." }, "copyrightYear": "2018"} </script> <meta property="og:url" content="https://visionlearning.com/en/library/chemistry/1/water/267"> <meta property="og:title" content="Water | Chemistry | Visionlearning" /> <meta property="og:type" content="website"> <meta property="og:site_name" content="Visionlearning"> <meta property="og:description" content="Water is a truly unusual and important substance. The unique chemical properties of water that give rise to surface tension, capillary action, and the low density of ice play vital roles in life as we know it. Floating ice protects aquatic organisms and keeps them from being frozen in the winter. Capillary action keeps plants alive. Surface tension allows lily pads to stay on the surface of a lake. In fact, water’s chemistry is so complex and important that scientists today are still striving to understand all the feats this simple substance can perform."> <meta property="og:image" content="https://visionlearning.com/images/logo.png"> <meta property="fb:admins" content="100000299664514"> <link rel="stylesheet" type="text/css" href="/css/visionlearning.css">  <link rel="stylesheet" type="text/css" href="/css/visionlearning-icons.css">  <link rel="preconnect" as="font" href="https://fonts.gstatic.com" crossorigin> <link href="https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,400;0,700;1,400;1,700&family=Schoolbell&display=swap" rel="stylesheet"> <style> textarea.myEditor { width: 90%; height: 350px; } </style> <script type="text/x-mathjax-config" src="/js/mathjax-config.js"></script> <script id="MathJax-script" async src="/js/mathjax/tex-svg.js"></script> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" 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<li><a href="/en/library/earth-science/6/factors-that-control-earths-temperature/234">Factors that Control Earth's Temperature</a></li> <li><a href="/en/library/earth-science/6/circulation-in-the-atmosphere/255">Circulation in the Atmosphere</a></li> </ul> </div> <button class="accordion__button" id="acc-button-hazards" data-accordion="button" aria-controls="acc-panel-hazards" aria-expanded="false"> <span class="accordion__button__label"> Hazards </span> </button> <div class="accordion__panel" id="acc-panel-hazards" data-accordion="panel" aria-labelledby="acc-button-hazards" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/earth-science/6/natural-hazards-and-risk/288">Natural Hazards and Risk</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-history" data-accordion="button" aria-controls="acc-panel-earth-history" aria-expanded="false"> <span class="accordion__button__label"> Earth History </span> </button> <div class="accordion__panel" 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aria-controls="acc-panel-ecology" aria-expanded="false"> <span class="accordion__button__label"> Ecology </span> </button> <div class="accordion__panel" id="acc-panel-ecology" data-accordion="panel" aria-labelledby="acc-button-ecology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/biodiversity-i/276">Biodiversity I</a></li> <li><a href="/en/library/environmental-science/61/biodiversity-ii/281">Biodiversity II</a></li> <li><a href="/en/library/environmental-science/61/ecosystem-services/279">Ecosystem Services</a></li> <li><a href="/en/library/environmental-science/61/population-biology/287">Population Biology</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-cycles" data-accordion="button" aria-controls="acc-panel-earth-cycles" aria-expanded="false"> <span class="accordion__button__label"> Earth Cycles </span> </button> <div class="accordion__panel" id="acc-panel-earth-cycles" data-accordion="panel" aria-labelledby="acc-button-earth-cycles" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/the-nitrogen-cycle/98">The Nitrogen Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-carbon-cycle/95">The Carbon Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-phosphorus-cycle/197">The Phosphorus Cycle</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/environmental-science/61/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-general-science" data-accordion="button" aria-controls="acc-panel-general-science" aria-expanded="false"> <span class="accordion__button__label"> General Science </span> </button> <div class="accordion__panel" id="acc-panel-general-science" data-accordion="panel" aria-labelledby="acc-button-general-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-methods" data-accordion="button" aria-controls="acc-panel-methods" aria-expanded="false"> <span class="accordion__button__label"> Methods </span> </button> <div class="accordion__panel" id="acc-panel-methods" data-accordion="panel" aria-labelledby="acc-button-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-scientific-method/45">The Scientific Method</a></li> </ul> </div> <button class="accordion__button" id="acc-button-measurement" data-accordion="button" aria-controls="acc-panel-measurement" aria-expanded="false"> <span class="accordion__button__label"> Measurement </span> </button> <div class="accordion__panel" id="acc-panel-measurement" data-accordion="panel" aria-labelledby="acc-button-measurement" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-metric-system/47">The Metric System</a></li> </ul> </div> <button class="accordion__button" id="acc-button-physical-properties" data-accordion="button" aria-controls="acc-panel-physical-properties" aria-expanded="false"> <span class="accordion__button__label"> Physical Properties </span> </button> <div class="accordion__panel" id="acc-panel-physical-properties" data-accordion="panel" aria-labelledby="acc-button-physical-properties" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/temperature/48">Temperature</a></li> <li><a href="/en/library/general-science/3/density-and-buoyancy/37">Density and Buoyancy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-math-in-science" data-accordion="button" aria-controls="acc-panel-math-in-science" aria-expanded="false"> <span class="accordion__button__label"> Math in Science </span> </button> <div class="accordion__panel" id="acc-panel-math-in-science" data-accordion="panel" aria-labelledby="acc-button-math-in-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-equations" data-accordion="button" aria-controls="acc-panel-equations" aria-expanded="false"> <span class="accordion__button__label"> Equations </span> </button> <div class="accordion__panel" id="acc-panel-equations" data-accordion="panel" aria-labelledby="acc-button-equations" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/unit-conversion/144">Unit Conversion</a></li> <li><a href="/en/library/math-in-science/62/linear-equations/194">Linear Equations</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-i/206">Exponential Equations I</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-ii/210">Exponential Equations II</a></li> <li><a href="/en/library/math-in-science/62/scientific-notation/250">Scientific Notation</a></li> <li><a href="/en/library/math-in-science/62/measurement/257">Measurement</a></li> </ul> </div> <button class="accordion__button" id="acc-button-statistics" data-accordion="button" aria-controls="acc-panel-statistics" aria-expanded="false"> <span class="accordion__button__label"> Statistics </span> </button> <div class="accordion__panel" id="acc-panel-statistics" data-accordion="panel" aria-labelledby="acc-button-statistics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/introduction-to-descriptive-statistics/218">Introduction to Descriptive Statistics</a></li> <li><a href="/en/library/math-in-science/62/introduction-to-inferential-statistics/224">Introduction to Inferential Statistics</a></li> <li><a href="/en/library/math-in-science/62/statistical-techniques/239">Statistical Techniques</a></li> </ul> </div> <button class="accordion__button" id="acc-button-trigonometric-functions" data-accordion="button" aria-controls="acc-panel-trigonometric-functions" aria-expanded="false"> <span class="accordion__button__label"> Trigonometric Functions </span> </button> <div class="accordion__panel" id="acc-panel-trigonometric-functions" data-accordion="panel" aria-labelledby="acc-button-trigonometric-functions" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/wave-mathematics/131">Wave Mathematics</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-physics" data-accordion="button" aria-controls="acc-panel-physics" aria-expanded="false"> <span class="accordion__button__label"> Physics </span> </button> <div class="accordion__panel" id="acc-panel-physics" data-accordion="panel" aria-labelledby="acc-button-physics" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-light-and-optics" data-accordion="button" aria-controls="acc-panel-light-and-optics" aria-expanded="false"> <span class="accordion__button__label"> Light and Optics </span> </button> <div class="accordion__panel" id="acc-panel-light-and-optics" data-accordion="panel" aria-labelledby="acc-button-light-and-optics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/the-nature-of-light/132">The Nature of Light</a></li> <li><a href="/en/library/physics/24/electromagnetism-and-light/138">Electromagnetism and Light</a></li> </ul> </div> <button class="accordion__button" id="acc-button-mechanics" data-accordion="button" aria-controls="acc-panel-mechanics" aria-expanded="false"> <span class="accordion__button__label"> Mechanics </span> </button> <div class="accordion__panel" id="acc-panel-mechanics" data-accordion="panel" aria-labelledby="acc-button-mechanics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/defining-energy/199">Defining Energy</a></li> <li><a href="/en/library/physics/24/waves-and-wave-motion/102">Waves and Wave Motion</a></li> <li><a href="/en/library/physics/24/gravity/118">Gravity</a></li> <li><a href="/en/library/physics/24/thermodynamics-i/200">Thermodynamics I</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-process-of-science" data-accordion="button" aria-controls="acc-panel-process-of-science" aria-expanded="false"> <span class="accordion__button__label"> Process of Science </span> </button> <div class="accordion__panel" id="acc-panel-process-of-science" data-accordion="panel" aria-labelledby="acc-button-process-of-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-introduction" data-accordion="button" aria-controls="acc-panel-introduction" aria-expanded="false"> <span class="accordion__button__label"> Introduction </span> </button> <div class="accordion__panel" id="acc-panel-introduction" data-accordion="panel" aria-labelledby="acc-button-introduction" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-process-of-science/176">The Process of Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-the-culture-of-science" data-accordion="button" aria-controls="acc-panel-the-culture-of-science" aria-expanded="false"> <span class="accordion__button__label"> The Culture of Science </span> </button> <div class="accordion__panel" id="acc-panel-the-culture-of-science" data-accordion="panel" aria-labelledby="acc-button-the-culture-of-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-nature-of-scientific-knowledge/185">The Nature of Scientific Knowledge</a></li> <li><a href="/en/library/process-of-science/49/scientists-and-the-scientific-community/172">Scientists and the Scientific Community</a></li> <li><a href="/en/library/process-of-science/49/scientific-ethics/161">Scientific Ethics</a></li> <li><a href="/en/library/process-of-science/49/scientific-institutions-and-societies/162">Scientific Institutions and Societies</a></li> </ul> </div> <button class="accordion__button" id="acc-button-ideas-in-science" data-accordion="button" aria-controls="acc-panel-ideas-in-science" aria-expanded="false"> <span class="accordion__button__label"> Ideas in Science </span> </button> <div class="accordion__panel" id="acc-panel-ideas-in-science" data-accordion="panel" aria-labelledby="acc-button-ideas-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/theories-hypotheses-and-laws/177">Theories, Hypotheses, and Laws</a></li> <li><a href="/en/library/process-of-science/49/scientific-controversy/181">Scientific Controversy</a></li> <li><a href="/en/library/process-of-science/49/creativity-in-science/182">Creativity in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-research-methods" data-accordion="button" aria-controls="acc-panel-research-methods" aria-expanded="false"> <span class="accordion__button__label"> Research Methods </span> </button> <div class="accordion__panel" id="acc-panel-research-methods" data-accordion="panel" aria-labelledby="acc-button-research-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-practice-of-science/148">The Practice of Science</a></li> <li><a href="/en/library/process-of-science/49/experimentation-in-scientific-research/150">Experimentation in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/description-in-scientific-research/151">Description in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/comparison-in-scientific-research/152">Comparison in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153">Modeling in Scientific Research</a></li> </ul> </div> <button class="accordion__button" id="acc-button-data" data-accordion="button" aria-controls="acc-panel-data" aria-expanded="false"> <span class="accordion__button__label"> Data </span> </button> <div class="accordion__panel" id="acc-panel-data" data-accordion="panel" aria-labelledby="acc-button-data" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/data-analysis-and-interpretation/154">Data Analysis and Interpretation</a></li> <li><a href="/en/library/process-of-science/49/uncertainty-error-and-confidence/157">Uncertainty, Error, and Confidence</a></li> <li><a href="/en/library/process-of-science/49/statistics-in-science/155">Statistics in Science</a></li> <li><a href="/en/library/process-of-science/49/using-graphs-and-visual-data-in-science/156">Using Graphs and Visual Data in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-communication" data-accordion="button" aria-controls="acc-panel-scientific-communication" aria-expanded="false"> <span class="accordion__button__label"> Scientific Communication </span> </button> <div class="accordion__panel" id="acc-panel-scientific-communication" data-accordion="panel" aria-labelledby="acc-button-scientific-communication" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/understanding-scientific-journals-and-articles/158">Understanding Scientific Journals and Articles</a></li> <li><a href="/en/library/process-of-science/49/utilizing-the-scientific-literature/173">Utilizing the Scientific Literature</a></li> <li><a href="/en/library/process-of-science/49/peer-review-in-scientific-publishing/159">Peer Review in Scientific Publishing</a></li> <li><a href="/en/library/process-of-science/49/the-how-and-why-of-scientific-meetings/186">The How and Why of Scientific Meetings</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-scientists-and-research" data-accordion="button" aria-controls="acc-panel-scientists-and-research" aria-expanded="false"> <span class="accordion__button__label"> Scientists and Research </span> </button> <div class="accordion__panel" id="acc-panel-scientists-and-research" data-accordion="panel" aria-labelledby="acc-button-scientists-and-research" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/scientists-and-research/58/from-stable-chromosomes-to-jumping-genes/184">From Stable Chromosomes to Jumping Genes</a></li> <li><a href="/en/library/scientists-and-research/58/an-elegant-experiment-to-test-the-process-of-dna-replication/187">An Elegant Experiment to Test the Process of DNA Replication</a></li> <li><a href="/en/library/scientists-and-research/58/the-founding-of-neuroscience/233">The Founding of Neuroscience</a></li> <li><a href="/en/library/scientists-and-research/58/tracking-endangered-jaguars-across-the-border/189">Tracking Endangered Jaguars across the Border</a></li> <li><a href="/en/library/scientists-and-research/58/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> <li><a href="/en/library/scientists-and-research/58/revolutionizing-medicine-with-monoclonal-antibodies/220">Revolutionizing Medicine with Monoclonal Antibodies</a></li> <li><a href="/en/library/scientists-and-research/58/uncovering-the-mysteries-of-chronic-mountain-sickness/238">Uncovering the Mysteries of Chronic Mountain Sickness</a></li> </ul> </div> <button class="accordion__button" id="acc-button-profiles-in-science" data-accordion="button" aria-controls="acc-panel-profiles-in-science" aria-expanded="false"> <span class="accordion__button__label"> Profiles in Science </span> </button> <div class="accordion__panel" id="acc-panel-profiles-in-science" data-accordion="panel" aria-labelledby="acc-button-profiles-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/luis-e.-miramontes/232">Luis E. Miramontes</a></li> <li><a href="/en/library/scientists-and-research/58/bernardo-houssay/237">Bernardo Houssay</a></li> <li><a href="/en/library/scientists-and-research/58/craig-lee/256">Craig Lee</a></li> <li><a href="/en/library/scientists-and-research/58/david-ho/241">David Ho</a></li> <li><a href="/en/library/scientists-and-research/58/louis-tompkins-wright/244">Louis Tompkins Wright</a></li> <li><a href="/en/library/scientists-and-research/58/carlos-j.-finlay/217">Carlos J. Finlay</a></li> <li><a href="/en/library/scientists-and-research/58/cecilia-payne/290">Cecilia Payne</a></li> <li><a href="/en/library/scientists-and-research/58/jazmin-scarlett/291">Jazmin Scarlett</a></li> <li><a href="/en/library/scientists-and-research/58/ramari-stewart/292">Ramari Stewart</a></li> <li><a href="/en/library/scientists-and-research/58/johnson-cerda/300">Johnson Cerda</a></li> <li><a href="/en/library/scientists-and-research/58/ellen-ochoa/201">Ellen Ochoa</a></li> <li><a href="/en/library/scientists-and-research/58/ruth-benerito/205">Ruth Benerito</a></li> <li><a href="/en/library/scientists-and-research/58/franklin-chang-díaz/219">Franklin Chang Díaz</a></li> <li><a href="/en/library/scientists-and-research/58/percy-lavon-julian/221">Percy Lavon Julian</a></li> <li><a href="/en/library/scientists-and-research/58/luis-walter-alvarez/229">Luis Walter Alvarez</a></li> <li><a href="/en/library/scientists-and-research/58/france-anne-dominic-córdova/230">France Anne-Dominic Córdova</a></li> </ul> </div> </div> </div> </div> </div> </li> <li>  <button class="button" data-toggle="dropdown">Chemistry </button> <div class="nav__dropdown box-shadow-1 padding-1"> <div class="accordion accordion--secondary font-size-sm"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-sub-button-atomic-theory-and-structure" data-accordion="button" aria-controls="acc-sub-panel-atomic-theory-and-structure" aria-expanded="false"> <span class="accordion__button__label"> Atomic Theory and Structure </span> </button> <div class="accordion__panel" id="acc-sub-panel-atomic-theory-and-structure" data-accordion="panel" aria-labelledby="acc-sub-button-atomic-theory-and-structure" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/chemistry/1/early-ideas-about-matter/49">Early Ideas about Matter</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-i/52">The Periodic Table of Elements I</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-ii/296">The Periodic Table of Elements II</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-iii/297">The Periodic Table of Elements III</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-iv/298">The Periodic Table of Elements IV</a></li> <li><a href="/en/library/chemistry/1/the-periodic-table-of-elements-v/299">The Periodic Table of Elements V</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-i/50">Atomic Theory I</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-ii/51">Atomic Theory II</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-iii/223">Atomic Theory III</a></li> <li><a href="/en/library/chemistry/1/atomic-theory-iv/231">Atomic Theory IV</a></li> <li><a href="/en/library/chemistry/1/the-mole-and-atomic-mass/53">The Mole and Atomic Mass</a></li> </ul> </div> <button class="accordion__button" 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href="/en/library/chemistry/1/kinetic-molecular-theory/251">Kinetic-Molecular Theory</a></li> <li><a href="/en/library/chemistry/1/solutions/266">Solutions</a></li> <li class="current">Water</li> </ul> </div> <button class="accordion__button" id="acc-sub-button-chemical-relationships" data-accordion="button" aria-controls="acc-sub-panel-chemical-relationships" aria-expanded="false"> <span class="accordion__button__label"> Chemical Relationships </span> </button> <div class="accordion__panel" id="acc-sub-panel-chemical-relationships" data-accordion="panel" aria-labelledby="acc-sub-button-chemical-relationships" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/chemistry/1/chemical-bonding/55">Chemical Bonding</a></li> <li><a href="/en/library/chemistry/1/stoichiometry/270">Stoichiometry</a></li> <li><a href="/en/library/chemistry/1/chemical-equations/268">Chemical Equations</a></li> <li><a href="/en/library/chemistry/1/acids-and-bases-i/271">Acids and Bases 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<main id="skip-header-content"> <div class="margin-bottom-5"> <div class="container narrow wide--lg margin-y-4"> <article class="module"> <header class="module__header"> <span class="subcategory"> <strong><em>Physical States and Properties</em></strong> </span> <h1>Water: <sub><em>Properties and behavior</em></sub></h1> <p class="byline">by Robin Marks, M.A., Anthony Carpi, Ph.D.</p> </header> <nav class="module__tabs"> <ul class="tabs-nav tabs-nav--pill tabs-nav--horizontal--md library"> <li> <a href="/en/library/chemistry/1/water/267/reading" class="is-active" aria-current="page" >Reading</a> </li> <li> <a href="/en/library/chemistry/1/water/267/quiz" >Quiz</a> </li> <li> <a href="/en/library/chemistry/1/water/267/resources" >Teach with this</a> </li> </ul> </nav> <script type="application/ld+json"> { "@context": "http://schema.org", "@type": "AudioObject", "contentUrl": "https://www.visionlearning.com/img/library/moduleAudio/module_267.mp3", "description": "Recording of Water : Water is a truly unusual and important substance. The unique chemical properties of water that give rise to surface tension, capillary action, and the low density of ice play vital roles in life as we know it. Floating ice protects aquatic organisms and keeps them from being frozen in the winter. Capillary action keeps plants alive. Surface tension allows lily pads to stay on the surface of a lake. In fact, water’s chemistry is so complex and important that scientists today are still striving to understand all the feats this simple substance can perform.", "encodingFormat": "mp3", "name": "module_267.mp3" } </script> <div class="module__audio"> <div class="audio-player border border-radius"> <audio id="audio"> <source src="https://www.visionlearning.com/img/library/moduleAudio/module_267.mp3" type="audio/mpeg"> Your browser does not support the audio element. </audio> <div class="audio-player__title"> <p>Listen to this reading</p> <span class="audio-player__timestamp" id="timestamp"> 00:00 </span> </div> <div class="audio-player__controls" id="controls"> <button class="button button--icon-only" id="play-pause-button"> <span class="icon icon-play" aria-hidden="true"></span> </button> <div class="audio-player__progress" id="progress-bar" tabindex="0" aria-valuemin="0" aria-valuemax="100" aria-valuenow="0" aria-label="Use arrow keys to forward or rewind the audio" role="slider"> <div class="audio-player__progress__fill"> <span class="audio-player__thumb"></span> </div> </div> <div class="audio-player__volume-container"> <button id="mute-button"> <span class="icon icon-volume"></span> </button> <div class="audio-player__volume" tabindex="0" aria-valuemin="0" aria-valuemax="100" aria-valuenow="100" aria-label="Use arrow keys to adjust volume" role="slider"> <div class="audio-player__volume__fill"> <span class="audio-player__thumb"></span> </div> </div> </div> </div> </div> </div> <hr class="module__divider" />  <div class="module__tools"> <aside class="module__tools__container border-radius box-shadow-1"> <div class="tabs tabs--toggle-mobile--lg" role="tablist"> <ul class="tab__buttons"> <li> <button class="button button--icon-over-text" aria-label="In this module" aria-controls="tab-panel-module__tools" aria-selected="true" role="tab"> <span class="button__icon"> <span class="icon icon-list" aria-hidden="true"></span> </span> <span class="button__text">Contents</span> </button> </li> <li> <button class="button button--icon-over-text" aria-controls="tab-panel-toggle-terms" aria-selected="false" role="tab"> <span class="button__icon"> <span class="icon icon-glossary-highlight"></span> </span> <span class="button__text">Glossary Terms</span> </button> </li> <li> <button class="button button--icon-over-text" aria-controls="tab-panel-toggle-ngss" aria-selected="false" role="tab"> <span class="button__icon"> <span class="icon icon-ngss" aria-hidden="true"></span> </span> <span class="button__text">NGSS</span> </button> </li> </ul> <div class="tabs__panel shown" id="tab-panel-module__tools" aria-labelledby="tab-button-module__tools" role="tabpanel"> <div class="table-of-contents"> <p class="table-of-contents__title"> Table of Contents </p> <ul class="table-of-contents__nav"> <li><a href="/en/library/chemistry/1/water/267#toc_1">What’s so special about water?</a> </li> <li><a href="/en/library/chemistry/1/water/267#toc_2">Properties of water that arise from hydrogen bonding</a> </li> <li> <ul> <li><a href="/en/library/chemistry/1/water/267#toc2_1">It floats!</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/water/267#toc2_2">The universal solvent</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/water/267#toc2_3">Cohesion and surface tension</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/chemistry/1/water/267#toc2_4">Adhesion and capillary action</a> </li> </ul> </li> </ul> </div> </div> <div class="tabs__panel" id="tab-panel-toggle-terms" aria-labelledby="tab-button-toggle-terms" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="termsToggleSwitch" id="terms-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Highlight Glossary Terms </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate glossary term highlighting to easily identify key terms within the module. Once highlighted, you can click on these terms to view their definitions. </em> </p> </div> </div> <div class="glossary-container"></div> </div> <div class="tabs__panel" id="tab-panel-toggle-ngss" aria-labelledby="tab-button-toggle-ngss" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="ngssToggleSwitch" id="ngss-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Show NGSS Annotations </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate NGSS annotations to easily identify NGSS standards within the module. Once highlighted, you can click on them to view these standards. </em> </p> </div> </div> <div class="ngss-container"></div> </div> </div> </aside> <div class="margin-3"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-9561344156007092" data-ad-slot="7634263342" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </div>     <div class="module__main"> <div class="module__main__container"> <div class="accordion">  <button class="accordion__button" id="acc-button-key-concepts" data-accordion="button" aria-controls="acc-panel-key-concepts" aria-expanded="true" tabindex="0"> Did you know? </button> <div class="accordion__panel shown show" id="acc-panel-key-concepts" data-accordion="panel" aria-labelledby="acc-button-key-concepts" role="region"> <div class="accordion__panel__content"> <p>Did you know that Galileo and his chief rival, Ludovico delle Colombe, had a famous debate on why ice floats on water? Delle Colombe claimed it was the broad and flat shape of ice, whereas Galileo claimed it was the lower density of ice that allowed it to float.</p> </div> </div>  <button class="accordion__button" id="acc-button-table-of-contents" data-accordion="button" aria-controls="acc-panel-table-of-contents" aria-expanded="false" tabindex="0"> Key concepts </button> <div class="accordion__panel" id="acc-panel-table-of-contents" data-accordion="panel" aria-labelledby="acc-button-table-of-contents" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <ul class="bulleted"> <li><p>Water has a number of unique properties that make it important in both the chemical and biological worlds.</li></p> <li><p>The polarity of water molecules allows liquid water to act as a "universal solvent," able to dissolve many ionic and polar covalent compounds.</li></p> <li><p>The polarity of water molecules also results in strong hydrogen bonds that give rise to phenomena such as surface tension, adhesion, and cohesion.</li></p> </ul> </div> </div>  <button class="accordion__button" id="acc-button-terms-you-should-know" data-accordion="button" aria-controls="acc-panel-terms-you-should-know" aria-expanded="false" tabindex="0"> Terms you should know </button> <div class="accordion__panel" id="acc-panel-terms-you-should-know" data-accordion="panel" aria-labelledby="acc-button-terms-you-should-know" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <dl> <dt>water, polarity, hydrogen bonds, surface tension, adhesion, cohesion</dt> <dd></dd> </dl> </div> </div> </div> <section> <p><em>This is an updated version of the module</em> <a href="https://www.visionlearning.com/en/library/Chemistry/1/Water/57"><em>Water</em></a>.</p> <p>Before we start, get yourself a glass of water. By the time you’ve reached the end, you’ll have a much greater appreciation for this miracle <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark>.</p><p>Got your glass? Now take a sip and think about all the roles water plays in your life. For one thing, your body can’t <mark class="term" data-term="function" data-term-def="Adaptations that influence how the animal interacts with other species. For example, animal function typically serves genetic and reproductive success." data-term-url="/en/glossary/view/function/13151">function</mark> more than a few days without it. You use water to wash yourself, your clothes, and your car. Water puts out fires, cooks our food, makes our soap get sudsy, and hundreds of other things. Water is absolutely essential to our lives on Earth.</p><p>Water is so central to our existence that you might be surprised to learn that it’s a rare and unusual substance in the <mark class="term" data-term="universe" data-term-def="The cosmos and everything that exists in it." data-term-url="/en/glossary/view/universe/5288">universe</mark>. Water is at once so vital and so scarce that exobiologists (scientists looking for life beyond Earth) set their sights on planets where water might exist. Life, it seems, can tough it out in acid, lye, extreme salt, extreme heat, and other conditions that would kill us humans. But it can’t exist without water.</p> <p><section id="toc_1" class=""> <h2>What’s so special about water?</h2></p> <p>Despite its scarcity across the <mark class="term" data-term="universe" data-term-def="The cosmos and everything that exists in it." data-term-url="/en/glossary/view/universe/5288">universe</mark>, water is so abundant on Earth that we aren’t always aware of how special it is. For starters, water is the only substance that exists naturally on our planet as a <mark class="term" data-term="solid" data-term-def="A collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and&hellip;" data-term-url="/en/glossary/view/solid/7571">solid</mark> (ice and snow), <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> (rivers, lakes, and oceans), and a <mark class="term" data-term="gas" data-term-def="The state of matter characterized by its non-condensed nature and ability to flow. Unlike liquids, molecules within a gas remain far&hellip;" data-term-url="/en/glossary/view/gas/8725">gas</mark> (water in the <mark class="term" data-term="atmosphere" data-term-def="The collective mass of gases that surrounds the Earth or another planet." data-term-url="/en/glossary/view/atmosphere/8529">atmosphere</mark> as humidity). As you might recall (or can read about in our module on <a href="/library/module_viewer.php?mid=120">States of Matter</a>), water <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> are in a different <mark class="term" data-term="energy" data-term-def="An abstract property defined as the capacity to do work. The basic forms of energy include chemical, electrical, mechanical, nuclear, and&hellip;" data-term-url="/en/glossary/view/energy/1497">energy</mark> state in each phase. The amount of energy required to go from solid to liquid and liquid to gas is related to how water molecules interact with each other. Those interactions are, in turn, related to how the <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atoms</mark> within a water molecule interact with each other.</p> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="9090201191"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> <p>Our <a href="/library/module_viewer.php?mid=55">Chemical Bonding: The Nature of the Chemical Bond</a> module discussed how a <mark class="term" data-term="dipole" data-term-def="An asymmetrical distribution of electrical charge across an object. Polar molecules contain a dipole." data-term-url="/en/glossary/view/dipole/1559">dipole</mark> forms across a water <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecule</mark>; in the <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bond</mark> between oxygen and hydrogen, the <mark class="term" data-term="electron" data-term-def="A subatomic particle with a negative charge of 1.60 × 10<sup>-19</sup> coulombs and a mass of 9.11 × 10<sup>-31</sup> kg. Electrons&hellip;" data-term-url="/en/glossary/view/electron/852">electrons</mark> are shared unequally, drawn a bit more to the oxygen. As a result, a partial negative <mark class="term" data-term="charge" data-term-def="A quantity of electricity." data-term-url="/en/glossary/view/charge/8258">charge</mark> (ð-) forms at the oxygen end of the molecule, and a partial positive charge (ð+) forms at each of the hydrogen <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atom</mark> ends (Figure 1).</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-9077-151117041135.jpg" alt="Figure 1: The dipoles arise in a water molecule because of unequal sharing of electrons." /> </button> <figcaption> <p><strong>Figure 1</strong>: The dipoles arise in a water molecule because of unequal sharing of electrons.</p> </figcaption> </figure> </div> <p>Since the hydrogen and oxygen <mark class="term" data-term="atom" data-term-def="The smallest unit of an element that retains the chemical properties of the element. Atoms can exist alone or in&hellip;" data-term-url="/en/glossary/view/atom/1509">atoms</mark> in the <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecule</mark> carry opposite (though partial) <mark class="term" data-term="charge" data-term-def="A quantity of electricity." data-term-url="/en/glossary/view/charge/8258">charges</mark>, nearby water molecules are attracted to each other like tiny little magnets. The electrostatic attraction between the ð+ hydrogen (ð stands for partial charge, a value less than the charge of an electron) and the ð- oxygen in adjacent molecules is called hydrogen <mark class="term" data-term="bonding" data-term-def="The act of fastening two atoms together." data-term-url="/en/glossary/view/bonding/8295">bonding</mark> (Figure 2).</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11931.png" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11931-180203120249.png" alt="Figure 2: Hydrogen bonds between water molecules. The slight negative charge on the oxygen atom is attracted to the slight positive charge on a hydrogen atom." /> </button> <figcaption> <p><strong>Figure 2</strong>: Hydrogen bonds between water molecules. The slight negative charge on the oxygen atom is attracted to the slight positive charge on a hydrogen atom.</p> </figcaption> </figure> </div> <p><mark id="ngss-341" class="ngss">Hydrogen <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bonds</mark> make water <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> "stick" together. These bonds are relatively weak compared to other types of covalent or <mark class="term" data-term="ionic bond" data-term-def="A chemical bond characterized by electrostatic attraction between ions of opposite charge. The formation of an ionic bond involves a&hellip;" data-term-url="/en/glossary/view/ionic+bond/1545">ionic bonds</mark>. In fact, they are often referred to as an attractive <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">force</mark> as opposed to a true bond. Yet, they have a big effect on how water behaves. There are many other <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compounds</mark> that form <mark class="term" data-term="hydrogen bond" data-term-def="A strong dipole-dipole attraction between two or more molecules, at least one of which has a hydrogen atom bonded to an&hellip;" data-term-url="/en/glossary/view/hydrogen+bond/1560">hydrogen bonds</mark>, but the ones between water molecules are particularly strong. Figure 2 shows why. If you look at the central molecule in this figure you see that the oxygen end of the molecule forms hydrogen bonds with two other water molecules; in addition, each hydrogen on the central molecule is attracted to a separate water molecule. As the illustration shows, each water molecule forms attractions with four other water molecules, a <mark class="term" data-term="network" data-term-def="An interconnected system; an interrelated net-like arrangement of parts." data-term-url="/en/glossary/view/network/8740">network</mark> of connections that makes the hydrogen <mark class="term" data-term="bonding" data-term-def="The act of fastening two atoms together." data-term-url="/en/glossary/view/bonding/8295">bonding</mark> in water particularly strong and lends the substance its many unique properties.</mark></p></section> <section id="toc_2"> <h2>Properties of water that arise from hydrogen bonding</h2></section> <section id="toc2_1"><h3>It floats!</h3><p>Now it’s time to make use of that glass of water. If you have some ice cubes, drop one in your glass. You’ll notice that it floats. Its ability to bob to the top of the water line means that the ice (water in its <mark class="term" data-term="solid" data-term-def="A collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and&hellip;" data-term-url="/en/glossary/view/solid/7571">solid</mark> state) is less <mark class="term" data-term="dense" data-term-def="Compact, packed close together; having a high mass in relation to volume." data-term-url="/en/glossary/view/dense/8273">dense</mark> than <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> water. (To review <mark class="term" data-term="density" data-term-def="A measure of the compactness of a substance given by the mass per unit volume (d = m/v). Common units of&hellip;" data-term-url="/en/glossary/view/density/863">density</mark> and buoyancy, see our <a href="/library/module_viewer.php?mid=37">Density</a> module) This isn’t a common state of affairs; if you put a chunk of solid wax into a vat of molten wax, it will sink toward the bottom (and possibly melt before it gets there).</p><p>To understand what causes ice to float but <mark class="term" data-term="solid" data-term-def="A collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and&hellip;" data-term-url="/en/glossary/view/solid/7571">solid</mark> wax to sink, let’s think first about what happens when a <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> turns to a solid (again, the <a href="/library/module_viewer.php?mid=120">States of Matter</a> module can be a handy review here). <mark id="ngss-342" class="ngss">In a liquid, the <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> have enough <mark class="term" data-term="kinetic" data-term-def="Relating to the motion of objects." data-term-url="/en/glossary/view/kinetic/8681">kinetic</mark> <mark class="term" data-term="energy" data-term-def="An abstract property defined as the capacity to do work. The basic forms of energy include chemical, electrical, mechanical, nuclear, and&hellip;" data-term-url="/en/glossary/view/energy/1497">energy</mark> to keep moving around. As molecules come near to each other, they are drawn together by intermolecular <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">forces</mark>. At the same time, molecules have enough <mark class="term" data-term="kinetic energy" data-term-def="The energy an object possesses by virtue of its motion. An object of mass m moving at velocity v has a&hellip;" data-term-url="/en/glossary/view/kinetic+energy/1505">kinetic energy</mark> to break free of those <mark class="term" data-term="force" data-term-url="/en/glossary/view/force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;">forces</mark> and be drawn to other nearby molecules. Thus the liquid flows because intermolecular attractions can be broken and reformed.</mark></p><p><mark id="ngss-343" class="ngss">A <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> freezes when the <mark class="term" data-term="kinetic" data-term-def="Relating to the motion of objects." data-term-url="/en/glossary/view/kinetic/8681">kinetic</mark> <mark class="term" data-term="energy" data-term-def="An abstract property defined as the capacity to do work. The basic forms of energy include chemical, electrical, mechanical, nuclear, and&hellip;" data-term-url="/en/glossary/view/energy/1497">energy</mark> is reduced (i.e. the temperature is reduced) enough that the attractive <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">forces</mark> between <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> can no longer be broken, and the molecules become locked in a static <mark class="term" data-term="lattice" data-term-def="A characteristic pattern formed by the spatial distribution of repeating units." data-term-url="/en/glossary/view/lattice/1549">lattice</mark>. For nearly all <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compounds</mark>, the lower energy and lack of movement between molecules means the molecules in a <mark class="term" data-term="solid" data-term-def="A collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and&hellip;" data-term-url="/en/glossary/view/solid/7571">solid</mark> are packed together more tightly than the liquid state. This is the case with wax and so solid wax is denser than the liquid and sinks.</mark></p><p><mark id="ngss-344" class="ngss">In the case of water, though, the shape of the <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecule</mark> and the strength of the hydrogen <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bonds</mark> affect the arrangement of the molecules. In <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> water, hydrogen <mark class="term" data-term="bonding" data-term-def="The act of fastening two atoms together." data-term-url="/en/glossary/view/bonding/8295">bonding</mark> pulls molecules closely together. As water freezes, the <mark class="term" data-term="dipole" data-term-def="An asymmetrical distribution of electrical charge across an object. Polar molecules contain a dipole." data-term-url="/en/glossary/view/dipole/1559">dipole</mark> ends with like <mark class="term" data-term="charge" data-term-def="A quantity of electricity." data-term-url="/en/glossary/view/charge/8258">charges</mark> <mark class="term" data-term="repel" data-term-def="To drive away, to force back, to resist, to ward off." data-term-url="/en/glossary/view/repel/8531">repel</mark> each other, forcing the molecules into a fixed <mark class="term" data-term="lattice" data-term-def="A characteristic pattern formed by the spatial distribution of repeating units." data-term-url="/en/glossary/view/lattice/1549">lattice</mark> in which they are farther from each other than they are in liquid water (Figure 3). More space between molecules makes the ice less <mark class="term" data-term="dense" data-term-def="Compact, packed close together; having a high mass in relation to volume." data-term-url="/en/glossary/view/dense/8273">dense</mark> than liquid water, and thus it floats.</mark></p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11932.png" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11932-180218110253.png" alt="Figure 3: When water freezes, the similarly-charged ends of the dipoles repel each other, pushing molecules apart. This means there is more space between molecules in the solid than in the liquid, making the solid (aka, ice) less dense." /> </button> <figcaption> <p><strong>Figure 3</strong>: When water freezes, the similarly-charged ends of the dipoles repel each other, pushing molecules apart. This means there is more space between molecules in the solid than in the liquid, making the solid (aka, ice) less dense.</p> </figcaption> </figure> </div> </section> <section id="toc2_2"><h3>The universal solvent</h3><p>Water is sometimes referred to as the “universal <mark class="term" data-term="solvent" data-term-def="The most abundant component in a homogeneous mixture of two or more substances." data-term-url="/en/glossary/view/solvent/1565">solvent</mark>,” because it dissolves more <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compounds</mark> than any other <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> known. The <mark class="term" data-term="polarity" data-term-def="The directionality of a magnetic field, which consists of a north and south pole of equal and opposite strength. Lines of&hellip;" data-term-url="/en/glossary/view/polarity/2877">polarity</mark> of the water <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecule</mark> allows it to readily dissolve other <mark class="term" data-term="polar" data-term-def="Carrying an electrical charge." data-term-url="/en/glossary/view/polar/8730">polar</mark> molecules, as well as <mark class="term" data-term="ion" data-term-def="An atom or molecule that has acquired an electrical charge by either gaining or losing electrons. A cation is an ion&hellip;" data-term-url="/en/glossary/view/ion/853">ions</mark>. (See our <a href="/en/library/Chemistry/1/Solutions/266">Solutions, solubility, and colligative properties</a> module for a deeper discussion of dissolution.)</p><p><mark id="ngss-345" class="ngss">This ability to dissolve substances is one of the properties that makes water vital for life. Most biological <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark>, such as <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark>, <mark class="term" data-term="protein" data-term-def="Macromolecules that are polymers of individual amino acids arranged in a chain and joined together by peptide bonds (and so also&hellip;" data-term-url="/en/glossary/view/protein/1594">proteins</mark>, and vitamins are <mark class="term" data-term="polar" data-term-def="Carrying an electrical charge." data-term-url="/en/glossary/view/polar/8730">polar</mark>, and important <mark class="term" data-term="ion" data-term-def="An atom or molecule that has acquired an electrical charge by either gaining or losing electrons. A cation is an ion&hellip;" data-term-url="/en/glossary/view/ion/853">ions</mark> such as sodium and potassium are also charged. In order for any of these <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compounds</mark> to carry out <mark class="term" data-term="function" data-term-def="Adaptations that influence how the animal interacts with other species. For example, animal function typically serves genetic and reproductive success." data-term-url="/en/glossary/view/function/13151">functions</mark> in the body, they have to be able to circulate in the blood and the <mark class="term" data-term="fluid" data-term-def="Able to flow because the intermolecular forces allow the molecules to move around in relation to one another. Both liquids and&hellip;" data-term-url="/en/glossary/view/fluid/8724">fluid</mark> within and between <mark class="term" data-term="cell" data-term-def="The basic structural unit of all living things." data-term-url="/en/glossary/view/cell/8286">cells</mark>, all of which are mostly water. Because of its <mark class="term" data-term="polarity" data-term-def="The directionality of a magnetic field, which consists of a north and south pole of equal and opposite strength. Lines of&hellip;" data-term-url="/en/glossary/view/polarity/2877">polarity</mark>, water is able to dissolve these and other substances, allowing their free movement around the body. A few biomolecules, such as fats and cholesterol, aren’t polar, and don’t dissolve in water – however, the body has developed unique ways to circulate and store these substances.</mark></p><p><mark id="ngss-346" class="ngss">Water is also able to dissolve gasses such as oxygen, allowing fish, plants, and other <mark class="term" data-term="aquatic" data-term-def="Related to, located in, or living in or on a body of water. Not terrestrial. Aquatic includes both freshwater and saltwater&hellip;" data-term-url="/en/glossary/view/aquatic/5619">aquatic</mark> life to access this dissolved oxygen (Figure 4). O<sub>2</sub> isn’t a <mark class="term" data-term="polar" data-term-def="Carrying an electrical charge." data-term-url="/en/glossary/view/polar/8730">polar</mark> <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecule</mark>; it dissolves because the polar <mark class="term" data-term="charge" data-term-def="A quantity of electricity." data-term-url="/en/glossary/view/charge/8258">charges</mark> in the water molecule induce a <mark class="term" data-term="dipole" data-term-def="An asymmetrical distribution of electrical charge across an object. Polar molecules contain a dipole." data-term-url="/en/glossary/view/dipole/1559">dipole</mark> in the oxygen, making it <mark class="term" data-term="soluble" data-term-def="Capable of being dissolved." data-term-url="/en/glossary/view/soluble/8532">soluble</mark> and so available to aquatic life.</mark> (Learn more about induced-dipole interactions in our <a href="/library/module_viewer.php?mid=222">Properties of Liquids</a> module.)</p> <div class="container margin-y-4 text-align-center"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-9561344156007092" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:inline-block;width:300px;height:250px" data-ad-client="ca-pub-9561344156007092" data-ad-slot="3321739899"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11933.jpg" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11933-180225030227.jpg" alt="Figure 4: When water and oxygen molecules meet (left), the negative dipole of water repels electrons around the oxygen molecule, creating a temporary dipole in the oxygen molecule (right)." /> </button> <figcaption> <p><strong>Figure 4</strong>: When water and oxygen molecules meet (left), the negative dipole of water repels electrons around the oxygen molecule, creating a temporary dipole in the oxygen molecule (right).</p> </figcaption> </figure> </div> </section> <section id="toc2_3"><h3>Cohesion and surface tension</h3><p>Let’s return to your water glass. Fill the glass just to the rim and stop. Then, slowly, add a little bit more. You’ll see that you can actually fill the glass a bit past its rim, and the edges of the water will round out against the glass, holding the water in.</p><p>Once again, <mark id="ngss-347" class="ngss">hydrogen <mark class="term" data-term="bonding" data-term-def="The act of fastening two atoms together." data-term-url="/en/glossary/view/bonding/8295">bonding</mark> is behind this act, resulting in <mark class="term" data-term="cohesion" data-term-def="The interaction of a molecule with other molecules of the same substance due to intermolecular forces such as hydrogen bonding. For&hellip;" data-term-url="/en/glossary/view/cohesion/8719">cohesion</mark>. Cohesion occurs when <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> of the same kind are attracted to each other. In the case of water, the molecules form strong hydrogen <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bonds</mark>, which hold the substance together. As a result, water is highly cohesive, in fact, it is the most cohesive of all non-metallic <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquids</mark>.</mark></p><p><mark id="ngss-348" class="ngss">Cohesion occurs throughout your glass of water, but it’s especially strong at the <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark>. <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">Molecules</mark> there have fewer neighbors (because they have none at the very surface), and so create stronger <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bonds</mark> with the molecules that are near them. The result is called <mark class="term" data-term="surface tension" data-term-def="The cohesive force exerted at the surface of a liquid that makes it tend to assume a spherical shape. Surface tension&hellip;" data-term-url="/en/glossary/view/surface+tension/1584">surface tension</mark>, or the ability of a substance to resist disruption to its surface. Dip your finger into your water glass and then pull it out. The drop that forms at the end of your fingertip is held together by surface tension.</mark></p><p>Surface tension was the misunderstood central player in a raucous <mark class="term" data-term="debate" data-term-def="A reasoned discussion of opposing points in an argument." data-term-url="/en/glossary/view/debate/8242">debate</mark> between <mark class="term" data-term="Galileo Galilei" data-term-def="The Italian physicist, mathematician, and astronomer born in Pisa in the Grand Duchy of Tuscany (1564-1642 CE). Among other things, Galileo&hellip;" data-term-url="/en/glossary/view/Galileo+Galilei/3724">Galileo Galilei</mark> and his chief rival, Ludovico delle Colombe in 1611. Delle Colombe, a philosopher, was at odds with some of Galileo’s ideas, including his explanation that ice floats on water because it is less <mark class="term" data-term="dense" data-term-def="Compact, packed close together; having a high mass in relation to volume." data-term-url="/en/glossary/view/dense/8273">dense</mark>. So the philosopher challenged Galileo to a debate, which delle Colombe believed would prove his own intellectual superiority.</p><p>Delle Colombe championed the (incorrect) idea that ice floats not because of <mark class="term" data-term="density" data-term-def="A measure of the compactness of a substance given by the mass per unit volume (d = m/v). Common units of&hellip;" data-term-url="/en/glossary/view/density/863">density</mark>, but because of its shape, which he saw as broad and flat, as is ice on a lake. To prove the “truth” of his <mark class="term" data-term="theory" data-term-def="A scientific theory is an explanation inferred from multiple lines of evidence for some broad aspect of the natural world and&hellip;" data-term-url="/en/glossary/view/theory/4854">theory</mark>, he used ebony wood, which is slightly denser than water, in a demonstration before an audience of curious spectators. He dropped a sphere of the wood into water, and it sank. He then placed a thin wafer of the wood flat on the water’s <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark>, and it floated. Delle Colombe pronounced himself the winner.</p><p>Galileo left frustrated. His <mark class="term" data-term="observation" data-term-def="1. The act of noticing something. 2. A record of that which has been noticed." data-term-url="/en/glossary/view/observation/8255">observations</mark> of the world gave him <mark class="term" data-term="evidence" data-term-def="Support for an idea, opinion, or hypothesis." data-term-url="/en/glossary/view/evidence/8243">evidence</mark> that his explanation, not delle Colombe’s, was right, but he couldn’t explain the <mark class="term" data-term="outcome" data-term-def="Result." data-term-url="/en/glossary/view/outcome/8247">outcome</mark> of delle Colombe’s <mark class="term" data-term="experiment" data-term-def="A test or trial carried out under controlled conditions so that specific actions can be performed and the results can be observed." data-term-url="/en/glossary/view/experiment/8292">experiment</mark>.</p><p><mark id="ngss-349" class="ngss">Had he known about <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark> and <mark class="term" data-term="dipole" data-term-def="An asymmetrical distribution of electrical charge across an object. Polar molecules contain a dipole." data-term-url="/en/glossary/view/dipole/1559">dipoles</mark> and hydrogen <mark class="term" data-term="bond" data-term-def="The force that holds together units such as atoms or molecules. <br> <b>[verb]</b> To hold or fasten units such as atoms or molecules together." data-term-url="/en/glossary/view/bond/8297">bonds</mark> at the time, Galileo certainly would have offered this explanation: When delle Colombe floated the thin ebony disc, he was taking advantage of the cohesive nature of water and the <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark> tension that arises from it (Figure 5). As the ebony wafer appeared to float on the water, the <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">force</mark> exerted by its <mark class="term" data-term="mass" data-term-def="A fundamental property of matter which is a numerical measure of the inertia of an object or the amount of matter&hellip;" data-term-url="/en/glossary/view/mass/3417">mass</mark> was distributed throughout the surface of the water beneath it. In other words, a single pinpoint-sized area of surface water only had to support the pinpoint-sized piece of ebony just above it. The <mark class="term" data-term="hydrogen bond" data-term-def="A strong dipole-dipole attraction between two or more molecules, at least one of which has a hydrogen atom bonded to an&hellip;" data-term-url="/en/glossary/view/hydrogen+bond/1560">hydrogen bonds</mark> between the water molecules were strong enough to support the <mark class="term" data-term="weight" data-term-def="A measure of the force exerted on an object by a gravitational field. The weight of an object equals its mass&hellip;" data-term-url="/en/glossary/view/weight/3418">weight</mark> of the disc. When delle Colombe placed the sphere in the water, however, the pinpoint-sized area that first touched the water bore the weight of the entire sphere, which was more than the water’s <mark class="term" data-term="surface tension" data-term-def="The cohesive force exerted at the surface of a liquid that makes it tend to assume a spherical shape. Surface tension&hellip;" data-term-url="/en/glossary/view/surface+tension/1584">surface tension</mark> could support. Had Galileo known this at the time, he could have disproved delle Colombe easily – had he simply pushed the wafer through the surface to break the surface tension, the wafer would have sunk.</mark></p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11934.png" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11934-180225030230.png" alt="Figure 5: Water molecules at the surface form stronger hydrogen bonds between them than do molecules in the rest of the water. These stronger bonds are responsible for surface tension." /> </button> <figcaption> <p><strong>Figure 5</strong>: Water molecules at the surface form stronger hydrogen bonds between them than do molecules in the rest of the water. These stronger bonds are responsible for surface tension.</p> <span class="credit">image ©USGS</span> </figcaption> </figure> </div> <p>This same <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark> tension is what allows leaves to stay at the surface of a lake and dewdrops to adhere to a spider’s web. Even some animals take advantage of this phenomenon – the Basilisk lizard (Figure 6), water striders, and a few other small animals and bugs appear to "walk" on water by taking advantage of the <mark class="term" data-term="surface tension" data-term-def="The cohesive force exerted at the surface of a liquid that makes it tend to assume a spherical shape. Surface tension&hellip;" data-term-url="/en/glossary/view/surface+tension/1584">surface tension</mark> of water.</p><div class="figure"><figure> <iframe src="//commons.wikimedia.org/wiki/File:Basiliscus_basiliscus_running_on_water_-_pone.0037300.s001.ogv?embedplayer=yes" width="320" height="240" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <figcaption><strong>Figure 6</strong>: A Basilisk lizard (<em>Basiliscus basiliscus</em>) runs on the water surface. Movie S1 from Minetti A, Ivanenko Y, Cappellini G, Dominici N, Lacquaniti F. "Humans Running in Place on Water at Simulated Reduced Gravity". <em>PLOS ONE</em>. DOI:10.1371/journal.pone.0037300</figcaption> </figure></div></section> <section id="toc2_4"><h3>Adhesion and capillary action</h3><p>For your next <mark class="term" data-term="observation" data-term-def="1. The act of noticing something. 2. A record of that which has been noticed." data-term-url="/en/glossary/view/observation/8255">observation</mark>, take another sip of water, and notice the side of the glass. Chances are you’ll see a few drops stuck to it. <mark class="term" data-term="gravity" data-term-def="The natural force that attracts a body toward the center of the Earth, or toward another physical body having mass." data-term-url="/en/glossary/view/gravity/11223">Gravity</mark> is pulling down on these drops, so something else must be keeping them stuck there. That something else is <mark id="ngss-350" class="ngss">adhesion, the attraction of water to other kinds of <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark>; in this case, the molecules that make up the glass. Because of the <mark class="term" data-term="polarity" data-term-def="The directionality of a magnetic field, which consists of a north and south pole of equal and opposite strength. Lines of&hellip;" data-term-url="/en/glossary/view/polarity/2877">polarity</mark> of the molecule, water exhibits stronger <mark class="term" data-term="adhesion" data-term-def="The interaction of a molecule with something other than itself, often related to mechanical or electrostatic forces. For example, water forms&hellip;" data-term-url="/en/glossary/view/adhesion/8718">adhesion</mark> to those <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surfaces</mark> that have some net electrical <mark class="term" data-term="charge" data-term-def="A quantity of electricity." data-term-url="/en/glossary/view/charge/8258">charge</mark>, and glass is one such surface. But place a drop of water on a non-polar surface, such as a piece of wax paper and you will see it take a different shape than one to which it adheres. On the wax paper, the water droplets take the shape of a true droplet because there is little adhesion and the cohesive <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">forces</mark> pull the drop into a sphere. But on glass you will see the droplets flatten and deform a bit as the adhesive <mark class="term" data-term="force" data-term-url="/en/glossary/view/force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;">forces</mark> draw it more to the surface of the glass.</mark></p><p><mark id="ngss-351" class="ngss">Both <mark class="term" data-term="cohesion" data-term-def="The interaction of a molecule with other molecules of the same substance due to intermolecular forces such as hydrogen bonding. For&hellip;" data-term-url="/en/glossary/view/cohesion/8719">cohesion</mark> and <mark class="term" data-term="adhesion" data-term-def="The interaction of a molecule with something other than itself, often related to mechanical or electrostatic forces. For example, water forms&hellip;" data-term-url="/en/glossary/view/adhesion/8718">adhesion</mark> (Figure 7) occur with many <mark class="term" data-term="compound" data-term-def="A material formed by the chemical combination of elements in defined proportions. Compounds can be chemically decomposed into simpler substances." data-term-url="/en/glossary/view/compound/1517">compounds</mark> besides water. Pressure sensitive tapes, for example, stick to <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surfaces</mark> because they are coated with a high <mark class="term" data-term="viscosity" data-term-def="The measurement of a fluid's resistance to shear or flow. Highly viscous fluids resist motion due to their molecular composition that&hellip;" data-term-url="/en/glossary/view/viscosity/7995">viscosity</mark> <mark class="term" data-term="fluid" data-term-def="Able to flow because the intermolecular forces allow the molecules to move around in relation to one another. Both liquids and&hellip;" data-term-url="/en/glossary/view/fluid/8724">fluid</mark> that adheres to the surface to which they are pressed. Generally, you can overcome this adhesive <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">force</mark> by pulling, for example – you can easily lift a Post-it® Note from a page. But sometimes the adhesive <mark class="term" data-term="force" data-term-url="/en/glossary/view/force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;">forces</mark> are stronger than the forces holding the surface together – pull tape off of a piece of paper and you remove pieces of the paper with the tape.</mark></p><p>Let’s return to our glass of water, and look inside to where the water <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark> meets the glass. The very edge of the water surface curves upward slightly on the glass. That’s also <mark class="term" data-term="adhesion" data-term-def="The interaction of a molecule with something other than itself, often related to mechanical or electrostatic forces. For example, water forms&hellip;" data-term-url="/en/glossary/view/adhesion/8718">adhesion</mark> – the water is drawn up the surface by adhesion with the glass. If you have a clear plastic straw, you can put one end of it into the water and see that the <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquid</mark> climbs up the straw a bit, above the surface of the remaining glass of water. It’s actually moving upward against gravity!</p><p>What’s happening in your straw is a phenomenon called capillary action (Figure 7). <mark id="ngss-352" class="ngss">Capillary action occurs in small tubes, where the <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark> area of the water is small, and the <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">force</mark> of adhesion—water’s attraction to the <mark class="term" data-term="polar" data-term-def="Carrying an electrical charge." data-term-url="/en/glossary/view/polar/8730">polar</mark> glass or other material—overcomes the force of <mark class="term" data-term="cohesion" data-term-def="The interaction of a molecule with other molecules of the same substance due to intermolecular forces such as hydrogen bonding. For&hellip;" data-term-url="/en/glossary/view/cohesion/8719">cohesion</mark> between those surface <mark class="term" data-term="molecule" data-term-def="A particle formed by the chemical bonding of two or more atoms. The molecule is the smallest particle of a&hellip;" data-term-url="/en/glossary/view/molecule/1518">molecules</mark>.</mark></p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11939.jpg" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11939-180225050216.jpg" alt="Figure 7: The attraction of water molecules to the sides of a narrow vessel (adhesion, red arrows) is stronger than the cohesion (orange arrows) drawing water molecules together. The result is capillary action, in which the force of adhesion pulls the fluid upwards (purple arrows)." /> </button> <figcaption> <p><strong>Figure 7</strong>: The attraction of water molecules to the sides of a narrow vessel (adhesion, red arrows) is stronger than the cohesion (orange arrows) drawing water molecules together. The result is capillary action, in which the force of adhesion pulls the fluid upwards (purple arrows).</p> </figcaption> </figure> </div> <p><mark id="ngss-353" class="ngss">Another way to see the effects of <mark class="term" data-term="adhesion" data-term-def="The interaction of a molecule with something other than itself, often related to mechanical or electrostatic forces. For example, water forms&hellip;" data-term-url="/en/glossary/view/adhesion/8718">adhesion</mark> and <mark class="term" data-term="cohesion" data-term-def="The interaction of a molecule with other molecules of the same substance due to intermolecular forces such as hydrogen bonding. For&hellip;" data-term-url="/en/glossary/view/cohesion/8719">cohesion</mark> is to compare the behavior of <mark class="term" data-term="polar" data-term-def="Carrying an electrical charge." data-term-url="/en/glossary/view/polar/8730">polar</mark> and nonpolar <mark class="term" data-term="liquid" data-term-def="The state of matter characterized by its condensed nature and ability to flow. Unlike gases, molecules within a liquid often experience&hellip;" data-term-url="/en/glossary/view/liquid/8727">liquids</mark>. When you put water in a <mark class="term" data-term="Test" data-term-def="This is a test glossary term." data-term-url="/en/glossary/view/Test/12984">test</mark> tube, adhesion makes the water along the edges move slightly upward and creates a concave meniscus. Liquid mercury, on the other hand, is not polar and therefore not attracted to glass. In a test tube, cohesion at the <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark> of the mercury is much stronger than adhesion to the glass. The <mark class="term" data-term="surface tension" data-term-def="The cohesive force exerted at the surface of a liquid that makes it tend to assume a spherical shape. Surface tension&hellip;" data-term-url="/en/glossary/view/surface+tension/1584">surface tension</mark> in the mercury forms a convex meniscus, much the same as the way water forms a slight bulge over the top of your very full glass</mark> (Figure 8).</p>  <div class="figure"> <figure> <button class="lightbox-button" data-lightbox-src="/img/library/large_images/image_11938.jpg" data-lightbox="image"> <img src="/img/library/modules/mid267/Image/VLObject-11938-180225040245.jpg" alt="Figure 8: Water and mercury behave differently in a test tube made of polar glass. Water adheres to the glass, bringing the sides upwards and forming a concave surface. Nonpolar mercury is not attracted to the glass. Cohesion between the mercury atoms creates surface tension that forms a convex surface." /> </button> <figcaption> <p><strong>Figure 8</strong>: Water and mercury behave differently in a test tube made of polar glass. Water adheres to the glass, bringing the sides upwards and forming a concave surface. Nonpolar mercury is not attracted to the glass. Cohesion between the mercury atoms creates surface tension that forms a convex surface.</p> <span class="credit">image ©USGS</span> </figcaption> </figure> </div> <p><mark id="ngss-354" class="ngss">Adhesion and capillary action are among the <mark class="term" data-term="force" data-term-def="An influence (a "push or pull") that changes the motion of a moving object (e.g., slows it down, speeds it up,&hellip;" data-term-url="/en/glossary/view/force/883">forces</mark> at play that help plants take up water (and dissolved nutrients) in their roots. Capillary action also keeps your eyes from drying out, as saline water flows from tiny ducts in the outer corners of your eyes. With each blink, you spread the water away from the duct, and capillary action brings more <mark class="term" data-term="fluid" data-term-def="Able to flow because the intermolecular forces allow the molecules to move around in relation to one another. Both liquids and&hellip;" data-term-url="/en/glossary/view/fluid/8724">fluid</mark> to the <mark class="term" data-term="surface" data-term-def="The outside or external part; the topside face of something." data-term-url="/en/glossary/view/surface/8275">surface</mark>.</mark></p><p>If you want to see capillary action at work, put a few drops of red food coloring in your glass of water, and then drop a stalk or two of leafy celery into it. After a day or two, your green celery will be streaked with red.</p></section> <footer class="module__main__footer"> <hr class="border-color-dark"> <p class="citation"> <em> Robin Marks, M.A., Anthony Carpi, Ph.D. “Water” Visionlearning Vol. CHE-4 (6), 2018. </em> </p>  <div class="title-list" id="refs" name="refs"> <p class="h6 title-list__title"> References </p> <ul class="title-list__list"> <li><p>Everts, S. (2013). Galileo on ice: Researchers commemorate the scientist's debate on why ice floats on water. <em>Chemical and Engineering News, 91</em>(34), p.28-29.</li> <li>Heilbron, J.L. (2012). <em>Galileo</em>. Oxford University Press.</li> <li>Lo Nostro, P. and Ninham, B.W. (2014). <em>Aqua incognita: Why ice floats on water and Galileo 400 years on</em>. Connor Court Press.</li> <li>MachLachlan, J. (1999). <em>Galileo Galilei: First physicist</em>. Oxford University Press.</li> <li>Whitehouse, D. (2009). <em>Renaissance genius: Galileo Galilei and his legacy to modern science</em>. Sterling Press.</li> </ul> </div>  <div class="title-list" name="further"> <p class="h6 title-list__title"> Further Reading </p> <ul class="grid grid--column-2--md grid--column-3--md gap-1"> <li> <a class="no-hover-focus height-100" href="/en/library/Chemistry/1/States-of-Matter/120"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_120-23061209064654.jpg" alt="States of Matter"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> States of Matter: <em>Kinetic molecular theory and phase transitions</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Chemistry/1/Chemical-Bonding/55"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_55-23061209065024.jpeg" alt="Chemical Bonding"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Chemical Bonding: <em>Ionic and covalent bonds and polarity</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Chemistry/1/Properties-of-Liquids/222"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_222-23061209064736.jpeg" alt="Properties of Liquids"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Properties of Liquids: <em>Intermolecular forces, cohesion, adhesion, and viscosity</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/General-Science/3/Density/37"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_37-23061210060349.jpg" alt="Density and Buoyancy"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Density and Buoyancy: <em>Definitions and units</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Chemistry/1/Solutions-Solubility-and-Colligative-Properties/266"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_266-23061209064829.jpeg" alt="Solutions"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Solutions: <em>Molarity, solubility, and colligative properties</em> </h2> </div> </article> </a> </li> </ul> </div> </footer> </div>    </article> </div> </div> </main> <script id="ngssCommentdata" type="application/json"> [{"ngss_tag_id":null,"type":"dci","tag":null,"name":null,"description":null,"comment":"The structure and interactions of matter at the bulk scale are determined by electrical forces within and between atoms.\r\n\r\nPS1.A: Structure and Properties of Matter","is_public":"1","mod_ngss_comment_id":"341","display_order":"1","dimension":"dci","dimension_full":"Disciplinary Core Ideas"},{"ngss_tag_id":null,"type":"dci","tag":null,"name":null,"description":null,"comment":"The structure and interactions of matter at the bulk scale are determined by electrical forces within and between atoms.\r\n\r\nPS1.A: Structure and Properties of Matter\r\n\r\nand\r\n\r\nThe functions and properties of natural and designed objects and systems can be inferred from their overall structure, 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