{"id":3072,"date":"2016-08-26T02:41:27","date_gmt":"2016-08-26T02:41:27","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/?post_type=chapter&#038;p=3072"},"modified":"2016-08-26T02:41:38","modified_gmt":"2016-08-26T02:41:38","slug":"valence-bond-theory","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/chapter\/valence-bond-theory\/","title":{"raw":"Valence Bond Theory","rendered":"Valence Bond Theory"},"content":{"raw":"<div class=\"x-ck12-data-objectives\">\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\n<ul id=\"x-ck12-NjBlYzdhNGQxYmFmNzhhZWE4MWU3ZTNjZGViZjBhNWE.-xof\">\r\n \t<li>Define valence bond theory.<\/li>\r\n \t<li>Describe how to use valence bond theory to explain aspects of covalent bonds.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div class=\"textbox examples\">\r\n<h3>What happens next?<\/h3>\r\n<div class=\"x-ck12-data-objectives\"><\/div>\r\n<p id=\"x-ck12-NDI2NGMxZWMwNTI0MTE2YjllMTk5ODk4NWRjNzQyNGI.-wle\"><span class=\"x-ck12-img-inline\"> <img class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19211543\/20140811155259365553.png\" alt=\"Bonding of fluorine atoms in the fluorine molecule\" width=\"500\" \/><\/span><\/p>\r\n<p id=\"x-ck12-NGU2YTk3MjA2MTJjOWVlNWRmZDA0NGVkZWQ2ZTY3MTQ.-ari\">We have seen that the old fish-hook idea of atoms connecting that Democritus liked so much just doesn\u2019t work.\u00a0 Electrons don\u2019t have little hooks on them, but they are the basis for connecting atoms to form molecules.\u00a0 You have learned how to write Lewis electron-dot structures for molecules and predict their shape using VSEPR theory.\u00a0 Now it is time to apply these abilities to understand how the electrons behave in their atomic orbitals when a covalent bond forms.<\/p>\r\n\r\n<\/div>\r\n<h2><span style=\"line-height: 1.5;\">Valence Bond Theory<\/span><\/h2>\r\n<\/div>\r\n<p id=\"x-ck12-NjZiZWViZjMwMzI5NGE0MDJmY2Y4M2ExNzBlNmU1MTY.-1yn\">You have learned that a covalent bond forms when the electron clouds of two atoms overlap with each other.\u00a0 In a simple H <sub> 2 <\/sub> molecule, the single electron in each atom becomes attracted to the nucleus of the other atom in the molecule as the atoms come closer together.\u00a0 An optimum distance, equal to the bond length, is eventually attained, and the potential energy reaches a minimum.\u00a0 A stable, single covalent bond has formed between the two hydrogen atoms.\u00a0 Other covalent bonds form in the same way as unpaired electrons from two atoms \u201cmatch up\u201d to form the bond.\u00a0 In a fluorine atom, there is an unpaired electron in one of the <em> 2p <\/em> orbitals.\u00a0 When a F <sub> 2 <\/sub> molecule forms, the <em> 2p <\/em> orbitals from each of the two atoms overlap to produce the F\u2212F covalent bond.\u00a0 The overlapping orbitals do not have to be of the same type.\u00a0 In a molecule of HF, the <em> 1s <\/em> orbital of the hydrogen atom overlaps with the <em> 2p <\/em> orbital of the fluorine atom (see figure below).<\/p>\r\n\r\n<div id=\"x-ck12-NjY0MTBiNGI0NzZjZTdmNDY4MmU0OGEwZTA2NTM2OGM.-xjv\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"500\"]<img id=\"x-ck12-OTgwNDUtMTM2MTg4Mjg0Mi0yNS00NC03\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19211544\/20140811155259446477.png\" alt=\"A molecule of hydrogen fluoride\" width=\"500\" height=\"332\" longdesc=\"A%20molecule%20of%20hydrogen%20fluoride%20%28HF%29.\" \/> Figure 1. A molecule of hydrogen fluoride (HF).[\/caption]\r\n\r\n<\/div>\r\n<p id=\"x-ck12-ZjIyMmNlNDlmZTkzZGJlNmQ0NzA1ZGNhNDdjZGEwMDY.-oxe\">In essence, any covalent bond results from the overlap of atomic orbitals.\u00a0 This idea forms the basis for a quantum mechanical theory called valence bond (VB) theory.\u00a0 In <strong> valence bond theory <\/strong> , the electrons in a molecule are assumed to occupy atomic orbitals of the individual atoms and a bond results from overlap of those orbitals.<\/p>\r\n\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Summary<\/h3>\r\n<ul id=\"x-ck12-NzJiMTJlZDQxOTMzYjhhNDM1MTEzM2Y2MGViYjIzMTU.-opz\">\r\n \t<li>Electrons occupy atomic orbitals.<\/li>\r\n \t<li>Covalent bonds result from the overlap of atomic orbitals.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Practice<\/h3>\r\n<p id=\"x-ck12-ZWI5MzMwYjg4ZDk5ODJlMmIzZWY5MmNlMjdiZTUxYWM.-eqe\">View the presentation at the link below and take the quizzes.<\/p>\r\n<p id=\"x-ck12-OTVlM2ZhYzU3MTM4ODA4NjgyNTU3NDZlODdkMDZlY2Q.-mck\"><a href=\"http:\/\/www.kentchemistry.com\/links\/bonding\/bondingflash.htm\"> http:\/\/www.kentchemistry.com\/links\/bonding\/bondingflash.htm<\/a><\/p>\r\n\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Review<\/h3>\r\n<ol id=\"x-ck12-MGRlNTVjZGFlZTI0MzdmNGYzNTcxYzMyMTg0YjUzOTM.-dqz\">\r\n \t<li>Where are electrons according to valence bond theory?<\/li>\r\n \t<li>How do covalent bonds form?<\/li>\r\n \t<li>Do the orbitals of the two electrons involved in the bond need to be the same?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<h2 class=\"x-ck12-data-problem-set\">Glossary<\/h2>\r\n<div class=\"x-ck12-data-vocabulary\">\r\n<ul id=\"x-ck12-OWQ3Y2Y0MWJhMTNhOWIwMWRhNGViMjFkZjhkOTY0M2M.-g12\">\r\n \t<li><strong> valence bond theory: <\/strong> The electrons in a molecule are assumed to occupy atomic orbitals of the individual atoms and a bond results from overlap of those orbitals.<\/li>\r\n<\/ul>\r\n[reveal-answer q=\"836080\"]Show References[\/reveal-answer]\r\n[hidden-answer a=\"836080\"]\r\n<h2>References<\/h2>\r\n<ol>\r\n \t<li>CK-12 Foundation - Jodi So.<\/li>\r\n \t<li>CK-12 Foundation - Jodi So. CK-12 Foundation.<\/li>\r\n<\/ol>\r\n[\/hidden-answer]\r\n\r\n<\/div>","rendered":"<div class=\"x-ck12-data-objectives\">\n<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<ul id=\"x-ck12-NjBlYzdhNGQxYmFmNzhhZWE4MWU3ZTNjZGViZjBhNWE.-xof\">\n<li>Define valence bond theory.<\/li>\n<li>Describe how to use valence bond theory to explain aspects of covalent bonds.<\/li>\n<\/ul>\n<\/div>\n<div class=\"textbox examples\">\n<h3>What happens next?<\/h3>\n<div class=\"x-ck12-data-objectives\"><\/div>\n<p id=\"x-ck12-NDI2NGMxZWMwNTI0MTE2YjllMTk5ODk4NWRjNzQyNGI.-wle\"><span class=\"x-ck12-img-inline\"> <img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19211543\/20140811155259365553.png\" alt=\"Bonding of fluorine atoms in the fluorine molecule\" width=\"500\" \/><\/span><\/p>\n<p id=\"x-ck12-NGU2YTk3MjA2MTJjOWVlNWRmZDA0NGVkZWQ2ZTY3MTQ.-ari\">We have seen that the old fish-hook idea of atoms connecting that Democritus liked so much just doesn\u2019t work.\u00a0 Electrons don\u2019t have little hooks on them, but they are the basis for connecting atoms to form molecules.\u00a0 You have learned how to write Lewis electron-dot structures for molecules and predict their shape using VSEPR theory.\u00a0 Now it is time to apply these abilities to understand how the electrons behave in their atomic orbitals when a covalent bond forms.<\/p>\n<\/div>\n<h2><span style=\"line-height: 1.5;\">Valence Bond Theory<\/span><\/h2>\n<\/div>\n<p id=\"x-ck12-NjZiZWViZjMwMzI5NGE0MDJmY2Y4M2ExNzBlNmU1MTY.-1yn\">You have learned that a covalent bond forms when the electron clouds of two atoms overlap with each other.\u00a0 In a simple H <sub> 2 <\/sub> molecule, the single electron in each atom becomes attracted to the nucleus of the other atom in the molecule as the atoms come closer together.\u00a0 An optimum distance, equal to the bond length, is eventually attained, and the potential energy reaches a minimum.\u00a0 A stable, single covalent bond has formed between the two hydrogen atoms.\u00a0 Other covalent bonds form in the same way as unpaired electrons from two atoms \u201cmatch up\u201d to form the bond.\u00a0 In a fluorine atom, there is an unpaired electron in one of the <em> 2p <\/em> orbitals.\u00a0 When a F <sub> 2 <\/sub> molecule forms, the <em> 2p <\/em> orbitals from each of the two atoms overlap to produce the F\u2212F covalent bond.\u00a0 The overlapping orbitals do not have to be of the same type.\u00a0 In a molecule of HF, the <em> 1s <\/em> orbital of the hydrogen atom overlaps with the <em> 2p <\/em> orbital of the fluorine atom (see figure below).<\/p>\n<div id=\"x-ck12-NjY0MTBiNGI0NzZjZTdmNDY4MmU0OGEwZTA2NTM2OGM.-xjv\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\n<div style=\"width: 510px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" id=\"x-ck12-OTgwNDUtMTM2MTg4Mjg0Mi0yNS00NC03\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19211544\/20140811155259446477.png\" alt=\"A molecule of hydrogen fluoride\" width=\"500\" height=\"332\" longdesc=\"A%20molecule%20of%20hydrogen%20fluoride%20%28HF%29.\" \/><\/p>\n<p class=\"wp-caption-text\">Figure 1. A molecule of hydrogen fluoride (HF).<\/p>\n<\/div>\n<\/div>\n<p id=\"x-ck12-ZjIyMmNlNDlmZTkzZGJlNmQ0NzA1ZGNhNDdjZGEwMDY.-oxe\">In essence, any covalent bond results from the overlap of atomic orbitals.\u00a0 This idea forms the basis for a quantum mechanical theory called valence bond (VB) theory.\u00a0 In <strong> valence bond theory <\/strong> , the electrons in a molecule are assumed to occupy atomic orbitals of the individual atoms and a bond results from overlap of those orbitals.<\/p>\n<div class=\"textbox key-takeaways\">\n<h3>Summary<\/h3>\n<ul id=\"x-ck12-NzJiMTJlZDQxOTMzYjhhNDM1MTEzM2Y2MGViYjIzMTU.-opz\">\n<li>Electrons occupy atomic orbitals.<\/li>\n<li>Covalent bonds result from the overlap of atomic orbitals.<\/li>\n<\/ul>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice<\/h3>\n<p id=\"x-ck12-ZWI5MzMwYjg4ZDk5ODJlMmIzZWY5MmNlMjdiZTUxYWM.-eqe\">View the presentation at the link below and take the quizzes.<\/p>\n<p id=\"x-ck12-OTVlM2ZhYzU3MTM4ODA4NjgyNTU3NDZlODdkMDZlY2Q.-mck\"><a href=\"http:\/\/www.kentchemistry.com\/links\/bonding\/bondingflash.htm\"> http:\/\/www.kentchemistry.com\/links\/bonding\/bondingflash.htm<\/a><\/p>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Review<\/h3>\n<ol id=\"x-ck12-MGRlNTVjZGFlZTI0MzdmNGYzNTcxYzMyMTg0YjUzOTM.-dqz\">\n<li>Where are electrons according to valence bond theory?<\/li>\n<li>How do covalent bonds form?<\/li>\n<li>Do the orbitals of the two electrons involved in the bond need to be the same?<\/li>\n<\/ol>\n<\/div>\n<h2 class=\"x-ck12-data-problem-set\">Glossary<\/h2>\n<div class=\"x-ck12-data-vocabulary\">\n<ul id=\"x-ck12-OWQ3Y2Y0MWJhMTNhOWIwMWRhNGViMjFkZjhkOTY0M2M.-g12\">\n<li><strong> valence bond theory: <\/strong> The electrons in a molecule are assumed to occupy atomic orbitals of the individual atoms and a bond results from overlap of those orbitals.<\/li>\n<\/ul>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q836080\">Show References<\/span><\/p>\n<div id=\"q836080\" class=\"hidden-answer\" style=\"display: none\">\n<h2>References<\/h2>\n<ol>\n<li>CK-12 Foundation &#8211; Jodi So.<\/li>\n<li>CK-12 Foundation &#8211; Jodi So. CK-12 Foundation.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-3072\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>Chemistry Concepts Intermediate. <strong>Authored by<\/strong>: Calbreath, Baxter, et al.. <strong>Provided by<\/strong>: CK12.org. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/\">http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/\">CC BY-NC: Attribution-NonCommercial<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17,"menu_order":17,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"Chemistry Concepts Intermediate\",\"author\":\"Calbreath, Baxter, et al.\",\"organization\":\"CK12.org\",\"url\":\"http:\/\/www.ck12.org\/book\/CK-12-Chemistry-Concepts-Intermediate\/\",\"project\":\"\",\"license\":\"cc-by-nc\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-3072","chapter","type-chapter","status-publish","hentry"],"part":2330,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/3072","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/users\/17"}],"version-history":[{"count":4,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/3072\/revisions"}],"predecessor-version":[{"id":3316,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/3072\/revisions\/3316"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/parts\/2330"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/3072\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/media?parent=3072"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapter-type?post=3072"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/contributor?post=3072"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/license?post=3072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}