atomic mass | Britannica

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Hit the Jackpot neon sign lights up casino window." width="200" height="200" /> </a> </div> <div class="card-body ilf-content"> <a class="font-weight-semi-bold d-block mb-5 font-16 ilf-title" href="/list/8-philosophical-puzzles-and-paradoxes" >Brain Games: 8 Philosophical Puzzles and Paradoxes</a> </div> </div> </div> </div> </div> </div> <button class="drawerToggle btn position-sticky border btn-xs btn-white btn-circle rounded-sm d-none d-lg-flex " type="button" aria-label="Toggle Drawer"> <em class="material-icons font-18 text-blue" data-icon="keyboard_arrow_left"></em> </button> </div> </div> <div class="col"> <div class="h-100 ml-0 pr-lg-0 "> <div class="h-100 grid gx-0 gx-lg-20"> <div class="h-100 col-sm d-flex flex-column"> <div class="toc-sticky-header d-none d-lg-none bg-gray-50 px-10 px-sm-30 position-sticky w-100 "> <div class="toc-sticky-header-inner-container align-items-center d-flex mx-auto h-100 w-100"> <button class="d-flex d-lg-none btn btn-sm btn-white text-blue border-2 border-gray-100 gtm-mobile-toc-header-button js-sections-button d-lg-none p-10"> <em class="material-icons my-n5 md-icon" data-icon="toc"></em> Contents </button> <div class="header-ai-ask-button-placeholder"></div> <div class="header-ai-summarize-button-placeholder"></div> </div> </div> <div class="grey-box w-100 grey-box-middle"> <div class="grey-box-content mx-auto w-100"> <script type="application/ld+json"> { "@context" : "https://schema.org", "@type" : "BreadcrumbList", "itemListElement" : [ { "@type" : "ListItem", "position" : 1, "item" : { "@id" : "https://www.britannica.com/browse/Science", "name": "Science" } } , { "@type" : "ListItem", "position" : 2, "item" : { "@id" : "https://www.britannica.com/browse/Physics", "name": "Physics" } } , { "@type" : "ListItem", "position" : 3, "item" : { "@id" : "https://www.britannica.com/browse/Matter-Energy", "name": "Matter & Energy" } } ] } </script> <nav class="breadcrumb mt-20 mb-30"> <span class="breadcrumb-item "> <a href="/" class="link-gray-600">Home</a> </span> <span class="breadcrumb-item "> <a class="link-gray-600" href="/browse/Science">Science</a> </span> <span class="breadcrumb-item "> <a class="link-gray-600" href="/browse/Physics">Physics</a> </span> <span class="breadcrumb-item "> <a class="link-gray-600" href="/browse/Matter-Energy">Matter & Energy</a> </span> </nav> <h1 class="mb-5">atomic mass: References & Edit History</h1> <div class="border-bottom mt-20"></div> <div id="More-Articles"> <h2 class="my-20">More Articles On This Topic</h2> <div class="mb-30"> <section><h3>Assorted References</h3><ul class="list-unstyled"></ul><ul class="list-unstyled"><li><strong>atomic weight</strong><ul class="list-unstyled"><li> <span class="index-xref">In <a href="https://www.britannica.com/science/atomic-weight#ref189873" class="md-crosslink " data-show-preview="true">atomic weight</a></span></li></ul></li><li><strong>mass spectrometry</strong><ul class="list-unstyled"><li> <span class="index-xref">In <a href="https://www.britannica.com/science/mass-spectrometry/Important-technical-adjuncts#ref619963" class="md-crosslink " data-show-preview="true">mass spectrometry: Atomic masses</a></span></li><li> <span class="index-xref">In <a href="https://www.britannica.com/science/spectroscopy/Lasers-for-RIS#ref620621" class="md-crosslink " data-show-preview="true">spectroscopy: Resonance-ionization mass spectrometry</a></span></li></ul></li><li><strong>properties of atoms</strong><ul class="list-unstyled"><li> <span class="index-xref">In <a href="https://www.britannica.com/science/atom/Atomic-mass-and-isotopes#ref496540" class="md-crosslink " data-show-preview="true">atom: Atomic mass and isotopes</a></span></li></ul></li></ul></section></div> </div> <div id="contributors" class="pt-20 mt-30 border-top"> <div id="contributors-atomic-mass"> <h2 class="mb-20">Article Contributors</h2> <h3 class="topic-contributors-subtitle h4">Primary Contributors</h3> <ul class="list-unstyled mt-10 mb-20 contributor-PRIMARY"> <li> <a href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419">The Editors of Encyclopaedia Britannica</a> </li> </ul> <h3 class="topic-contributors-subtitle h4">Other Encyclopedia Britannica Contributors</h3> <ul class="list-unstyled mt-10 mb-20 contributor-NON_PRIMARY_EB"> <li> <a href="/editor/Erik-Gregersen/6723">Erik Gregersen</a> </li> <li> <a href="/editor/William-L-Hosch/6481">William L. Hosch</a> </li> <li> <a href="/editor/Gloria-Lotha/7666594">Gloria Lotha</a> </li> <li> <a href="/editor/Melissa-Petruzzello/9400228">Melissa Petruzzello</a> </li> <li> <a href="/editor/Emily-Rodriguez/9852325">Emily Rodriguez</a> </li> <li> <a href="/editor/Grace-Young/7666614">Grace Young</a> </li> </ul> </div> </div> <div id="history" class="pt-20 border-top"> <div id="history-atomic-mass"> <h2 class="mb-20">Article History</h2> <div class="mw-100 overflow-scroll"> <table class="article-history table"> <thead> <tr> <th class="topic-history-type">Type</th> <th class="topic-history-description">Description</th> <th class="topic-history-contributor">Contributor</th> <th class="topic-history-date">Date</th> </tr> </thead> <tbody> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Modified link of Web site: Westfield State University - Department of Chemical and Physical Sciences - Atomic Mass.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Grace-Young/7666614">Grace Young</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Jul 02, 2024</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Open Library Publishing Platform - Enhanced Introductory College Chemistry - Atomic Mass.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Gloria-Lotha/7666594">Gloria Lotha</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Feb 01, 2024</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Chemistry LibreTexts - Atomic Masses.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Gloria-Lotha/7666594">Gloria Lotha</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Nov 24, 2023</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> <span class="topic-history-diff-link link-blue" data-diff="/30/10130-008">Links and videos added.</span></td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419">The Editors of Encyclopaedia Britannica</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> May 30, 2023</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> Added a cross-reference to atomic mass unit.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Melissa-Petruzzello/9400228">Melissa Petruzzello</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Mar 17, 2023</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Westfield State University - Atomic Mass.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Gloria-Lotha/7666594">Gloria Lotha</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Dec 30, 2022</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Chemistry LibreTexts - Atomic Mass.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Emily-Rodriguez/9852325">Emily Rodriguez</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Oct 10, 2022</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> <span class="topic-history-diff-link link-blue" data-diff="/30/10130-005">Added material about the atomic mass unit also being called the dalton.</span></td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Erik-Gregersen/6723">Erik Gregersen</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Apr 06, 2021</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Angelo State University - Atomic Masses.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Emily-Rodriguez/9852325">Emily Rodriguez</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Sep 19, 2016</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="link"></em> </td> <td> Add new Web site: Westfield State University - Department of Chemical and Physical Sciences - Atomic Mass.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Emily-Rodriguez/9852325">Emily Rodriguez</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Sep 19, 2016</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> <span class="topic-history-diff-link link-blue" data-diff="/30/10130-004">Updated value of atomic mass unit from 1.66053878 x 10^-24 gram to 1.660539040 x 10^-24 gram.</span></td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Erik-Gregersen/6723">Erik Gregersen</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Nov 19, 2015</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> <span class="topic-history-diff-link link-blue" data-diff="/30/10130-003">Changed value of atomic mass unit from 1.66053873 x 10^-24 gram to 1.66053878 x 10^-24 gram.</span></td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/Erik-Gregersen/6723">Erik Gregersen</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Aug 11, 2010</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> <span class="topic-history-diff-link link-blue" data-diff="/30/10130-002">Article revised and updated.</span></td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/William-L-Hosch/6481">William L. Hosch</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Dec 08, 2006</td> </tr> <tr> <td class="history-type"> <em class="material-icons " data-icon="edit"></em> </td> <td> Article added to new online database.</td> <td class="history-contributor"> <ul class="list-unstyled"> <li data-type="contributor"> <a href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419">The Editors of Encyclopaedia Britannica</a></li> </ul> </td> <td data-type="date" class="text-nowrap"> Jul 20, 1998</td> </tr> </tbody> </table> </div> <div id="md-topic-diff" class="d-none"> <div class="md-modal-header"> </div> <div class="md-modal-body"> <div class="md-topic-diff-header-container"> <div class="md-topic-diff-header"> <div class="grid"> <div class="col"> <div class="md-topic-diff-header-browse"> <span>View Changes: </span> <div title="previous change" id="md-topic-diff-previous" class="md-topic-diff-pn disabled"></div> <div title="next change" id="md-topic-diff-next" class="md-topic-diff-pn"></div> </div> </div> <div class="col justify-content-center d-flex align-items-center align-self-center"> <div class="h3">Article History</div> </div> <div class="col"> <div class="md-topic-diff-header-info"> <div>Revised: <span id="md-topic-diff-date"></span></div> <div>By: <span id="md-topic-diff-contributor"></span></div> </div> <em class="md-close material-icons" data-icon="close"></em> </div> </div> </div> </div> <div id="md-topic-diff-container" class="md-overlay-container mt-50 mt-sm-0"></div> </div> </div> </div> </div> </div> </div> </div> <aside class="col-md-da-320"></aside> </div> </div> </div> </div></div> </div> </main> <div id="md-footer"></div> <footer class="md-footer footer-wrapper hide-on-edit"> <div class="footer-bck"> <DIV class="marketing-FOOTER_NEWSLETTER marketing-content" data-marketing-id="FOOTER_NEWSLETTER"><div class="md-footer-newsletter-form pt-10 mb-30 mx-15 mx-sm-120"> <div class="font-18"> <strong>History at your fingertips –</strong> Sign up here to see what happened On This Day, every day in your inbox! </div> <div class="p-30"> <div class="newsletter-form-container"> <form class="newsletter-form" method="post" action="/newsletter-subscription/EB_ON_THIS_DAY"> <div class="form-group grid d-flex justify-content-center"> <div class="col-sm-50 col-100"> <label class="sr-only" for="enter-your-email">Enter your email</label> <input id="enter-your-email" type="email" name="email" class="form-control font-18 p-10" placeholder="Enter your email" pattern="[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$" required> </div> <div class="col-sm-auto col-100 mt-5 mt-sm-0"> <button type="submit" class="btn btn-outline-white" style="width: 100%; height:100%;">Subscribe</button> </div> </div> <div class="text-white pt-30 text-opacity"> By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica.<br> Click here to view our <a class="link-white text-decoration-underline" href="https://corporate.britannica.com/privacy-policy2" target="_blank" rel="noopener nofollow">Privacy Notice</a>. 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