How does the electron come back down in energy level after absorbing a photon?

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</h1> </div> <div class="p-description"> <ul class="listInline listInline--bullet"> <li> <span data-xf-init="tooltip" title="Level: Intermediate (Undergrad)" ><span class="prefix inter" dir="auto">I</span></span> </li> <li> <i class="fa--xf fal fa-user" aria-hidden="true" title="Thread starter"></i> <span class="u-srOnly">Thread starter</span> <span>jjschwartz1</span> </li> <li> <i class="fa--xf fal fa-clock" aria-hidden="true" title="Start date"></i> <span class="u-srOnly">Start date</span> <time class="u-dt" dir="auto" datetime="2024-10-18T18:48:41-0500" data-time="1729295321" data-date-string="Oct 18, 2024" data-time-string="6:48 PM" title="Oct 18, 2024 at 6:48 PM">Oct 18, 2024</time> </li> <li> <dl class="tagList tagList--thread-1066386 "> <dt> <i class="fa--xf fal fa-tags" aria-hidden="true" title="Tags"></i> <span class="u-srOnly">Tags</span> </dt> <dd> <span class="js-tagList"> <a href="/tags/electron/" data-xf-init="preview-tooltip" data-preview-url="/tags/electron/preview" class="tagItem tagItem--tag_electron" dir="auto"> Electron </a> <a href="/tags/energy-level/" data-xf-init="preview-tooltip" data-preview-url="/tags/energy-level/preview" class="tagItem tagItem--tag_energy-level" dir="auto"> Energy level </a> <a href="/tags/excited/" data-xf-init="preview-tooltip" data-preview-url="/tags/excited/preview" class="tagItem tagItem--tag_excited" dir="auto"> Excited </a> </span> </dd> </dl> </li> </ul> </div> </div> <script src="https://www.physicsforums.com/check-for-tex.js" defer></script> <div class="block block--messages" data-xf-init="" data-type="post" data-href="/inline-mod/" data-search-target="*"> <span class="u-anchorTarget" id="posts"></span> <div class="block-outer"></div> <div class="block-outer js-threadStatusField"></div> <div class="block-container lbContainer" data-xf-init="lightbox select-to-quote old-new-message-indicator" data-sv-live-content-time-element-selector=".message-attribution-main time.u-dt" data-message-selector=".js-post" data-lb-id="thread-1066386" data-lb-universal="0"> <div class="block-body js-replyNewMessageContainer">  <article class="message message--post js-post js-inlineModContainer " data-author="jjschwartz1" data-content="post-7126666" id="js-post-7126666" > <span class="u-anchorTarget" id="post-7126666"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-18T18:48:41-0500" data-time="1729295321" data-date-string="Oct 18, 2024" data-time-string="6:48 PM" title="Oct 18, 2024 at 6:48 PM">Oct 18, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7126666/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #1 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" > <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="421017">jjschwartz1</span></span>   <span class="threadstarter" data-xf-init="tooltip" title="Thread Starter"><i class="fal fa-user-edit"></i></span>   </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>4</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>2</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7126666" data-lb-caption-desc="jjschwartz1 · Oct 18, 2024 at 6:48 PM"> <article class="message-body js-selectToQuote"> <div > <div class="bbWrapper">A common explanation for the origin of (some) color is that a material absorbs a, say, red photon and an electron moves from one energy level to a higher energy level, the difference in energy being the energy of the red photon. The material then appears bluish having absorbed the red light.<br /> <br /> What happens to that excited electron? If it just falls down to the original energy level it will emit red light and the material won't have color. There must be other processes.<br /> <br /> Thank you in advance for any insights.</div> </div> <div class="js-selectToQuoteEnd"> </div> <div class="googleads_fixed"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-6580726045122001" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-6580726045122001" data-ad-slot="3049969336" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </article> </div> </div> <footer class="message-footer"> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span 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It is certainly not the case for solids.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="jjschwartz1" data-content="post-7126684" id="js-post-7126684" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7126684/"> <meta itemprop="parentItem" itemscope 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</section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7126684" data-lb-caption-desc="jjschwartz1 · Oct 18, 2024 at 11:21 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Among other more valid references, this youtube video produced by the American Chemical Society, beginning at 1:07, <span data-s9e-mediaembed="youtube"><span><span data-s9e-mediaembed-c2l="youtube" data-s9e-mediaembed-c2l-background="linear-gradient(0deg,rgba(0,0,0,0) 0,rgba(0,0,0,0) 72%,rgba(0,0,0,.04) 79%,rgba(0,0,0,.1) 83%,rgba(0,0,0,.25) 88%,rgba(0,0,0,.67) 100%),url(https://i.ytimg.com/vi/6xgBSQwqAuE/hqdefault.jpg) 50% 50% / cover" data-s9e-mediaembed-c2l-oembed-id="6xgBSQwqAuE" data-s9e-mediaembed-c2l-oembed-title="Every Other Video About Color is Wrong" data-s9e-mediaembed-iframe='["allowfullscreen","","scrolling","no","allow","autoplay","src","https:\/\/www.youtube.com\/embed\/6xgBSQwqAuE?autoplay=1"]'></span></span></span></div> </div> <div class="js-selectToQuoteEnd"> </div> <div class="googleads_fixed"> <script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ca-pub-6580726045122001" crossorigin="anonymous"></script>  <ins class="adsbygoogle" style="display:block" data-ad-client="ca-pub-6580726045122001" data-ad-slot="5961342082" data-ad-format="auto" data-full-width-responsive="true"></ins> <script> (adsbygoogle = window.adsbygoogle || []).push({}); </script> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div 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js-lbContainer " data-lb-id="post-7126706" data-lb-caption-desc="PeroK · Oct 19, 2024 at 2:46 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 421017" data-quote="jjschwartz1" data-source="post: 7126666" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> jjschwartz1 said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> A common explanation for the origin of (some) color is that a material absorbs a, say, red photon and an electron moves from one energy level to a higher energy level, the difference in energy being the energy of the red photon. The material then appears bluish having absorbed the red light.<br /> <br /> What happens to that excited electron? If it just falls down to the original energy level it will emit red light and the material won't have color. There must be other processes.<br /> <br /> Thank you in advance for any insights. </div> </div> </blockquote>I suspect the full answer to this question may be quite complicated and that different types of objects have colour for different reasons. One key point to note is this:<br /> <br /> The light from the Sun or a lamp is largely in the visible (and infrared) spectrum. This determines the spectrum incident upon an object. Some of that spectrum may be absorbed. Note that visible light is relatively energetic, so the absorbtion will excite a molecule from the ground state to a relatively high excited state. Typically, a molecule has a large number of possible excited energy levels.<br /> <br /> When the molecule reemits the light, however, it may do this in several stages, resulting in several emissions each of a lower energy (longer wavelength) than the original incident light. The object may emit light generally in the invisible, infrared part of the spectrum. It's possible that statistically very little light is re-emitted in the visible spectrum.<br /> <br /> This would tie in with the thermodynamic picture of the incident light heating the body, as the light is absorbed, then the energy is radiated according to the blackbody spectrum, which would be largely invisible at normal temperatures.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> <div class="message-lastEdit"> Last edited: <time class="u-dt" dir="auto" datetime="2024-10-19T02:58:36-0500" data-time="1729324716" data-date-string="Oct 19, 2024" data-time-string="2:58 AM" title="Oct 19, 2024 at 2:58 AM" itemprop="dateModified">Oct 19, 2024</time> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="2" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>Demystifier</bdi> and <bdi>Hornbein</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="Vanadium 50" data-content="post-7126742" id="js-post-7126742" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7126742/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7126742"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-19T08:29:31-0500" data-time="1729344571" data-date-string="Oct 19, 2024" data-time-string="8:29 AM" title="Oct 19, 2024 at 8:29 AM" itemprop="datePublished">Oct 19, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7126742/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #5 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/vanadium-50.110252/"> <meta itemprop="url" content="https://www.physicsforums.com/members/vanadium-50.110252/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/vanadium-50.110252/" class="username " dir="auto" data-user-id="110252" data-xf-init="member-tooltip"><span itemprop="name">Vanadium 50</span></a></span>    <div class="post-badges"> <div class="post-badge badge-shield" data-xf-init="tooltip" title="Retired Mentor"> <i class="fa--xf fal fa-shield" aria-hidden="true" style="font-size:12px;color:#990033;"></i><span> Staff Emeritus</span> </div> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-book" data-xf-init="tooltip" title="Verified Expert in Academia"> <i class="fa--xf fal fa-book" aria-hidden="true"></i><span> Education Advisor</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>35,001</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>21,674</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7126742" data-lb-caption-desc="Vanadium 50 · Oct 19, 2024 at 8:29 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Solids don't have orbitals in the way you are imagining. They have energy bands. The energy to move an electron from band to band varies with the size of the band. Further, electrons can gain or lose energy as they travel in a band.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="2" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>Demystifier</bdi> and <bdi>PeroK</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="snorkack" data-content="post-7126815" id="js-post-7126815" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7126815/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7126815"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-19T15:50:12-0500" data-time="1729371012" data-date-string="Oct 19, 2024" data-time-string="3:50 PM" title="Oct 19, 2024 at 3:50 PM" itemprop="datePublished">Oct 19, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7126815/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #6 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/snorkack.436348/"> <meta itemprop="url" content="https://www.physicsforums.com/members/snorkack.436348/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="436348"><span itemprop="name">snorkack</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,302</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>511</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7126815" data-lb-caption-desc="snorkack · Oct 19, 2024 at 3:50 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 421017" data-quote="jjschwartz1" data-source="post: 7126666" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> jjschwartz1 said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> A common explanation for the origin of (some) color is that a material absorbs a, say, red photon and an electron moves from one energy level to a higher energy level, the difference in energy being the energy of the red photon. The material then appears bluish having absorbed the red light.<br /> <br /> What happens to that excited electron? If it just falls down to the original energy level it will emit red light and the material won't have color. There must be other processes. </div> </div> </blockquote>If the deexcitation takes place by emitting same frequency light (in the case, red), then the photons would be spontaneously emitted in random directions. Absorption and reemission would thus work as scattering, and the substance would be blue in transmitted light, but red in scattered light, including backscattered light.<br /> A good example of a substance which is similar colour as gas and as liquid is bromine. Simple homoatomic diatomic gas too. Does a Br<sub>2</sub> molecule in gas have orbitals? <br /> How much do the spectra of gaseous, liquid and solid bromine differ? And does liquid bromine have bands instead of orbitals?<br /> For water, there is a nice comparison of spectra:<br /> <a href="https://en.wikipedia.org/wiki/File:Water_infrared_absorption_coefficient_large.gif" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://en.wikipedia.org/wiki/File:Water_infrared_absorption_coefficient_large.gif</a><br /> but that´s somewhat more complex, infrared absorption, compared to a simple diatomic molecule.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>sophiecentaur</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="sophiecentaur" data-content="post-7128773" id="js-post-7128773" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7128773/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7128773"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-29T08:30:21-0500" data-time="1730208621" data-date-string="Oct 29, 2024" data-time-string="8:30 AM" title="Oct 29, 2024 at 8:30 AM" itemprop="datePublished">Oct 29, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7128773/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #7 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/sophiecentaur.199289/"> <meta itemprop="url" content="https://www.physicsforums.com/members/sophiecentaur.199289/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/sophiecentaur.199289/" class="username " dir="auto" data-user-id="199289" data-xf-init="member-tooltip"><span itemprop="name">sophiecentaur</span></a></span>    <div class="post-badges"> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>29,732</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>7,230</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7128773" data-lb-caption-desc="sophiecentaur · Oct 29, 2024 at 8:30 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 436348" data-quote="snorkack" data-source="post: 7126815" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> snorkack said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Does a Br2 molecule in gas have orbitals? </div> </div> </blockquote>Bromine is one of the few gasses with very visible colour. Could that be because it is dense and has high van der Waal's forces - meaning it is more likely to absorb light? That would tie in with the fact that solids and liquids tend to exhibit colour, where most gases do not.<br /> There is a great temptation to discuss what goes on in solids and liquids by referring to a simple Hydrogen Atom model; in fact it's nothing like that because there are many more possible energy levels involved (bands not lines)</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="DrClaude" data-content="post-7128777" id="js-post-7128777" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7128777/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7128777"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-29T09:00:20-0500" data-time="1730210420" data-date-string="Oct 29, 2024" data-time-string="9:00 AM" title="Oct 29, 2024 at 9:00 AM" itemprop="datePublished">Oct 29, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7128777/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #8 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/drclaude.461323/"> <meta itemprop="url" content="https://www.physicsforums.com/members/drclaude.461323/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/drclaude.461323/" class="username " dir="auto" data-user-id="461323" data-xf-init="member-tooltip"><span class="username--staff username--moderator" itemprop="name">DrClaude</span></a></span>    <div class="post-badges"> <div class="post-badge badge-mentor" data-xf-init="tooltip" title="PF Community Staff"> <i class="fa--xf fal fa-user-graduate" aria-hidden="true"></i><span> Mentor</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>8,477</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>5,688</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7128777" data-lb-caption-desc="DrClaude · Oct 29, 2024 at 9:00 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="" data-quote="" data-source="" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> The origin of the color of the halogens stems from the excitation between the highest occupied π* molecular orbital and the lowest unoccupied σ* molecular orbital. The energy gap between the HOMO and LUMO decreases according to F2 > Cl2 > Br2 > I2. The amount of energy required for excitation depends upon the size of the atom. Fluorine is the smallest element in the group and the force of attraction between the nucleus and the outer electrons is very large. As a result, it requires a large excitation energy and absorbs violet light (high energy) and so appears pale yellow. On the other hand, iodine needs significantly less excitation energy and absorbs yellow light of low energy. Thus it appears dark violet. Using similar arguments, it is possible to explain the greenish yellow color of chlorine and the reddish brown color of bromine. </div> </div> </blockquote><a href="https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Inorganic_Chemistry_(LibreTexts)/08%3A_Chemistry_of_the_Main_Group_Elements/8.13%3A_The_Halogens/8.13.01%3A_Physical_Properties_of_the_Halogens" target="_blank" class="link link--external" rel="noopener">https://chem.libretexts.org/Bookshe.../8.13.01:_Physical_Properties_of_the_Halogens</a></div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--7" data-reaction-id="7"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Informative" title="Informative" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>sophiecentaur</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="snorkack" data-content="post-7128820" id="js-post-7128820" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7128820/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7128820"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-29T13:22:15-0500" data-time="1730226135" data-date-string="Oct 29, 2024" data-time-string="1:22 PM" title="Oct 29, 2024 at 1:22 PM" itemprop="datePublished">Oct 29, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7128820/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #9 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/snorkack.436348/"> <meta itemprop="url" content="https://www.physicsforums.com/members/snorkack.436348/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="436348"><span itemprop="name">snorkack</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,302</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>511</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7128820" data-lb-caption-desc="snorkack · Oct 29, 2024 at 1:22 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 199289" data-quote="sophiecentaur" data-source="post: 7128773" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> sophiecentaur said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Bromine is one of the few gasses with very visible colour. <br /> There is a great temptation to discuss what goes on in solids and liquids by referring to a simple Hydrogen Atom model; in fact it's nothing like that because there are many more possible energy levels involved (bands not lines) </div> </div> </blockquote>And solids and liquids are too complex compared to hydrogen atom. <br /> Halogens are a good next step to look at - just two atoms and a symmetry because the atoms are identical. Just a few extra degrees of freedom compared to hydrogen atom.<br /> One obvious degree of freedom to look at is the internuclear distance.<br /> Something I recalled in pondering it is Franck-Condon principle.<br /> Movement of nuclei is slow compared to excitation of electrons.<br /> Therefore, when molecular orbitals are excited, they are often excited to vibrationally excited states of the electronically excited state of the system.<br /> I said "system" because I am not sure whether to call it "molecule". When a halogen molecule has one electron excited to antibonding orbital, is it excited to a bound (and therefore quantized) state of the molecule, or an unbound continuum state of two dissociated atoms propelled away from each other by repulsion of their opposite wavefunction orbitals?</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" 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data-time-string="1:53 PM" title="Oct 29, 2024 at 1:53 PM" itemprop="datePublished">Oct 29, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7128826/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #10 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/sophiecentaur.199289/"> <meta itemprop="url" content="https://www.physicsforums.com/members/sophiecentaur.199289/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/sophiecentaur.199289/" class="username " dir="auto" data-user-id="199289" data-xf-init="member-tooltip"><span itemprop="name">sophiecentaur</span></a></span>    <div class="post-badges"> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>29,732</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>7,230</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7128826" data-lb-caption-desc="sophiecentaur · Oct 29, 2024 at 1:53 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 461323" data-quote="DrClaude" data-source="post: 7128777" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> DrClaude said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> <a href="https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Inorganic_Chemistry_(LibreTexts)/08%3A_Chemistry_of_the_Main_Group_Elements/8.13%3A_The_Halogens/8.13.01%3A_Physical_Properties_of_the_Halogens" target="_blank" class="link link--external" rel="nofollow ugc noopener">https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Inorganic_Chemistry_(LibreTexts)/08:_Chemistry_of_the_Main_Group_Elements/8.13:_The_Halogens/8.13.01:_Physical_Properties_of_the_Halogens</a> </div> </div> </blockquote>What about the attenuation of the light with those strong colours? Could there be something to do with the probability of photon/electron interaction (i.e. do other gasses just absorb EM of other frequencies just as much?)<br /> PS or is it to do with the fact that the absorption is broader band so more electrons are stimulated by photons of a range of frequencies? That could make sense to me.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="sophiecentaur" data-content="post-7128827" id="js-post-7128827" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7128827/"> <meta itemprop="parentItem" itemscope 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message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/sophiecentaur.199289/"> <meta itemprop="url" content="https://www.physicsforums.com/members/sophiecentaur.199289/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/sophiecentaur.199289/" class="username " dir="auto" data-user-id="199289" data-xf-init="member-tooltip"><span itemprop="name">sophiecentaur</span></a></span>    <div class="post-badges"> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs 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said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Solids don't have orbitals in the way you are imagining. </div> </div> </blockquote>That's a popular misconception.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--6" data-reaction-id="6"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Skeptical" title="Skeptical" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>berkeman</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="Vanadium 50" data-content="post-7129029" id="js-post-7129029" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7129029/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7129029"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-30T09:45:38-0500" data-time="1730299538" data-date-string="Oct 30, 2024" data-time-string="9:45 AM" title="Oct 30, 2024 at 9:45 AM" 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class="post-badge badge-shield" data-xf-init="tooltip" title="Retired Mentor"> <i class="fa--xf fal fa-shield" aria-hidden="true" style="font-size:12px;color:#990033;"></i><span> Staff Emeritus</span> </div> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-book" data-xf-init="tooltip" title="Verified Expert in Academia"> <i class="fa--xf fal fa-book" aria-hidden="true"></i><span> Education Advisor</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>35,001</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>21,674</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129029" data-lb-caption-desc="Vanadium 50 · Oct 30, 2024 at 9:45 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper">Can you suggest a better one-sentence explanation?</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" 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message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7129123/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #13 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/sophiecentaur.199289/"> <meta itemprop="url" content="https://www.physicsforums.com/members/sophiecentaur.199289/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/sophiecentaur.199289/" class="username " dir="auto" data-user-id="199289" data-xf-init="member-tooltip"><span itemprop="name">sophiecentaur</span></a></span>    <div class="post-badges"> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>29,732</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>7,230</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129123" data-lb-caption-desc="sophiecentaur · Oct 30, 2024 at 3:58 PM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 199289" data-quote="sophiecentaur" data-source="post: 7128827" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> sophiecentaur said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> That's a popular misconception. </div> </div> </blockquote>The word "orbital" is hardly accurate to describe the way an electron 'moves' anywhere but in a simple molecule. What would it 'go round' in the middle of a block of plastic or a crystal? Or through a piece of copper.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="snorkack" data-content="post-7129228" id="js-post-7129228" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7129228/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7129228"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-31T03:08:27-0500" data-time="1730362107" data-date-string="Oct 31, 2024" data-time-string="3:08 AM" title="Oct 31, 2024 at 3:08 AM" itemprop="datePublished">Oct 31, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7129228/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #14 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/snorkack.436348/"> <meta itemprop="url" content="https://www.physicsforums.com/members/snorkack.436348/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="436348"><span itemprop="name">snorkack</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,302</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>511</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129228" data-lb-caption-desc="snorkack · Oct 31, 2024 at 3:08 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 199289" data-quote="sophiecentaur" data-source="post: 7129123" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> sophiecentaur said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> The word "orbital" is hardly accurate to describe the way an electron 'moves' anywhere but in a simple molecule. What would it 'go round' in the middle of a block of plastic or a crystal? Or through a piece of copper. </div> </div> </blockquote>But you seem to agree with Vanadium 50 on the issue.<br /> When Vanadium 50 captures an electron and turns into Titanium 50 in a block of solid metal vanadium, is the electron taken from 1s (or even 2s or 3s) orbital of the specific Vanadium 50 atom? Or is it taken from a conduction band of metal vanadium?<br /> When Vanadium 50 captures an electron and turns into Titanium 50 in a molecule of VCl<sub>4</sub> in frozen VCl<sub>4</sub> (melts at -25 degrees), is the electron taken from 1s (or even 2s or 3s) orbital of the specific Vanadium 50 atom? Or is it taken from a molecular orbital, shared with the 4 Cl atoms but not the other VCl<sub>4</sub> molecules, bound by dispersion forces alone? Or from a band of the solid (and nonconductive) VCl<sub>4</sub>?<br /> VCl<sub>4</sub> incidentally can also be excited by visible light - it is bright red. It can also be observed as a gas, because it boils at 148 degrees.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="1" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList is-active"> <ul class="reactionSummary"> <li><span class="reaction reaction--small reaction--1" data-reaction-id="1"><i aria-hidden="true"></i><img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="reaction-sprite js-reaction" alt="Like" title="Like" /></span></li> </ul> <span class="u-srOnly">Likes</span> <bdi>dextercioby</bdi> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="sophiecentaur" data-content="post-7129244" id="js-post-7129244" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7129244/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7129244"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-10-31T05:50:05-0500" data-time="1730371805" data-date-string="Oct 31, 2024" data-time-string="5:50 AM" title="Oct 31, 2024 at 5:50 AM" itemprop="datePublished">Oct 31, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7129244/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #15 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/sophiecentaur.199289/"> <meta itemprop="url" content="https://www.physicsforums.com/members/sophiecentaur.199289/" /> <div class="message-userDetails"> <span class="message-name"><a href="/members/sophiecentaur.199289/" class="username " dir="auto" data-user-id="199289" data-xf-init="member-tooltip"><span itemprop="name">sophiecentaur</span></a></span>    <div class="post-badges"> <div class="post-badge badge-university" data-xf-init="tooltip" title="Verified Expert in Science and Math"> <i class="fa--xf fal fa-university" aria-hidden="true"></i><span> Science Advisor</span> </div> <div class="post-badge badge-star" data-xf-init="tooltip" title="Click to Support PF"> <i class="fa--xf fal fa-star" aria-hidden="true"></i><span> Gold Member</span> </div> </div>  </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>29,732</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>7,230</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129244" data-lb-caption-desc="sophiecentaur · Oct 31, 2024 at 5:50 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 436348" data-quote="snorkack" data-source="post: 7129228" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> snorkack said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> But you seem to agree with </div> </div> </blockquote>There is no "but" involved. I agree with his (<a href="https://www.physicsforums.com/members/110252/" class="username" data-xf-init="member-tooltip" data-user-id="110252" data-username="@Vanadium 50">@Vanadium 50</a> 's) and your ideas but I question why the term "orbital" is ever used to describe anything but the very basics of the Hydrogen Atom - particularly when QM stresses that the shapes that you see in the associated graphics are probability densities. <br /> Having learned my Physics without an A Level Chemistry past I was just confused by the term Orbital when nothing goes 'around' anywhere. I'd be surprised if no one else would have been helped by the use of a better term. <br /> Too late to change now, though. (The term AND me!)</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="DaTario" data-content="post-7129424" id="js-post-7129424" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7129424/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7129424"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-11-01T05:03:45-0500" data-time="1730455425" data-date-string="Nov 1, 2024" data-time-string="5:03 AM" title="Nov 1, 2024 at 5:03 AM" itemprop="datePublished">Nov 1, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7129424/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #16 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/datario.33942/"> <meta itemprop="url" content="https://www.physicsforums.com/members/datario.33942/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="33942"><span itemprop="name">DaTario</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>1,092</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>46</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129424" data-lb-caption-desc="DaTario · Nov 1, 2024 at 5:03 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 493650" data-quote="PeroK" data-source="post: 7126706" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> PeroK said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> When the molecule reemits the light, however, it may do this in several stages, resulting in several emissions each of a lower energy (longer wavelength) than the original incident light. The object may emit light generally in the invisible, infrared part of the spectrum. It's possible that statistically very little light is re-emitted in the visible spectrum. </div> </div> </blockquote>A process that is possibly important in explaining the phenomenon of color by subtractive synthesis is the fact that once excited, the electron decays and emits a photon in a superposition of momentum states (Weisskopf-Wigner theory for spontaneous decay). In practice, this means that the red photon is not generally directed toward the same retina that collected the other incident and reflected photons. In many cases, this photon must head toward the sample of matter itself, giving rise to reabsorption or thermal processes.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> </div> </div> </div> </article>  <article class="message message--post js-post js-inlineModContainer " data-author="snorkack" data-content="post-7129436" id="js-post-7129436" itemscope itemtype="https://schema.org/Comment" itemid="https://www.physicsforums.com/posts/7129436/"> <meta itemprop="parentItem" itemscope itemid="https://www.physicsforums.com/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/" /> <span class="u-anchorTarget" id="post-7129436"></span> <div class="message-header"> <header class="message-attribution message-attribution--split"> <ul class="message-attribution-main listInline "> <li class="u-concealed"> <time class="u-dt" dir="auto" datetime="2024-11-01T07:07:14-0500" data-time="1730462834" data-date-string="Nov 1, 2024" data-time-string="7:07 AM" title="Nov 1, 2024 at 7:07 AM" itemprop="datePublished">Nov 1, 2024</time> </li> </ul> <ul class="message-attribution-opposite message-attribution-opposite--list "> <li> <span style="cursor:pointer;" data-xf-init="share-tooltip" data-href="/posts/7129436/share" aria-label="Share" role="button" rel="nofollow"> <i class="fa--xf fal fa-share-alt" aria-hidden="true"></i> </span> </li> <li> #17 </li> </ul> </header> </div> <div class="message-inner"> <div class="message-cell message-cell--user"> <section class="message-user" itemprop="author" itemscope itemtype="https://schema.org/Person" itemid="https://www.physicsforums.com/members/snorkack.436348/"> <meta itemprop="url" content="https://www.physicsforums.com/members/snorkack.436348/" /> <div class="message-userDetails"> <span class="message-name"><span class="username " dir="auto" data-user-id="436348"><span itemprop="name">snorkack</span></span></span>     </div> <div class="message-userExtras"> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-comments fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Messages"></i></dt> <dd>2,302</dd> </dl> <dl class="pairs pairs--justified"> <dt><i class="fa--xf fal fa-thumbs-up fa-fw" aria-hidden="true" data-xf-init="tooltip" title="Reaction score"></i></dt> <dd>511</dd> </dl> </div> <span class="message-userArrow"></span> </section> </div> <div class="message-cell message-cell--main"> <div class="message-main js-quickEditTarget"> <div class="message-content js-messageContent"> <div class="message-userContent lbContainer js-lbContainer " data-lb-id="post-7129436" data-lb-caption-desc="snorkack · Nov 1, 2024 at 7:07 AM"> <article class="message-body js-selectToQuote"> <div itemprop="text"> <div class="bbWrapper"><blockquote data-attributes="member: 33942" data-quote="DaTario" data-source="post: 7129424" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> DaTario said: </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> A process that is possibly important in explaining the phenomenon of color by subtractive synthesis is the fact that once excited, the electron decays and emits a photon in a superposition of momentum states (Weisskopf-Wigner theory for spontaneous decay). In practice, this means that the red photon is not generally directed toward the same retina that collected the other incident and reflected photons. In many cases, this photon must head toward the sample of matter itself, giving rise to reabsorption or thermal processes. </div> </div> </blockquote>If the only effect is reemitting the photon in a random and new direction, at the same frequency, over time small relative to reaction time and with 100% efficiency, it looks like scattering. And selective scatterer of e. g. red light should be red in reflected light, blue in transmitted light.</div> </div> <div class="js-selectToQuoteEnd"> </div> </article> </div> </div> <footer class="message-footer"> <div class="message-microdata" itemprop="interactionStatistic" itemtype="https://schema.org/InteractionCounter" itemscope> <meta itemprop="userInteractionCount" content="0" /> <meta itemprop="interactionType" content="https://schema.org/LikeAction" /> </div> <div class="reactionsBar js-reactionsList "> </div> <div class="js-historyTarget message-historyTarget toggleTarget" data-href="trigger-href"></div> </footer> <script> if (typeof parseNewPost == 'function') { $(document).ajaxStop(parseNewPost(7129436)); } </script> </div> </div> </div> </article> </div> </div> </div> <form action="/threads/how-does-the-electron-come-back-down-in-energy-level-after-absorbing-a-photon.1066386/add-reply" method="post" class="block js-quickReply" data-xf-init="attachment-manager quick-reply 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The material then appears bluish having absorbed the red light.\n\nWhat happens to that excited electron? If it just falls down to the original energy level it will emit red light and the material won't have color. There must be other processes.\n\nThank you in advance for any insights." }, "publisher": { "@type": "Organization", "name": "Physics Forums: Science Discussion, Homework Help, Articles", "alternateName": "Physics Forums", "description": "Join Physics Forums, where students, scientists, and enthusiasts come together to explore and discuss the current understanding and practice of various scientific fields.", "url": "https://www.physicsforums.com", "logo": "https://www.physicsforums.com/styles/physicsforums/images/physics-forums-logo-og.png" } } </script> <script type="text/javascript" src="https://www.physicsforums.com/copyright.js" defer></script> <script> function parseNewPost(postid) { var newpost = document.getElementById("js-post-" + postid), npa = [newpost]; MathJax.typeset(npa); } function parsePreview() { var preview = document.getElementsByClassName("xfPreview"); MathJax.typeset(preview); } function parseNewConversationPost(postid) { var newpost = document.getElementsByClassName("convMessage-" + postid); MathJax.typeset(newpost); } function parseNewProfilePost(postid) { var newpost = document.getElementById("js-profilePost-" + postid), npa = [newpost]; MathJax.typeset(npa); } function parseTooltip() { MathJax.typeset(); } </script> </body> </html>

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How does the electron come back down in energy level after absorbing a photon?