Answer:<\/strong><\/p>\n\n\n\n The lone pair on nitrogen in ammonia (NH\u2083) has less s-character<\/em> than the lone pairs in phosphine (PH\u2083), arsine (AsH\u2083), and stibine (SbH\u2083) due to differences in effective nuclear charge (Z_eff)<\/strong> and principal quantum number (n)<\/strong>. As we move down Group 15 from nitrogen to antimony, the principal quantum number increases (from n = 2<\/em> for N to n = 5<\/em> for Sb), which affects the shape, energy, and localization of the lone pair orbital. In NH\u2083, the lone pair resides in a hybrid orbital with more p-character, while in the heavier hydrides, the lone pair resides more in an s-type orbital. This trend is influenced by both the spatial extent of orbitals (via radial maxima<\/strong>) and the energetic cost of hybridization due to primogenicity<\/strong>.<\/p>\n\n\n\n Explanation:<\/strong><\/p>\n\n\n\n In NH\u2083, nitrogen uses sp\u00b3 hybrid orbitals for bonding and accommodating its lone pair. The lone pair resides in one of these sp\u00b3 hybrids, and the molecule adopts a trigonal pyramidal shape. The nitrogen atom has a relatively small atomic radius, high Z_eff<\/strong>, and its valence electrons occupy the second shell (n = 2<\/em>). The s and p orbitals in this shell are relatively close in energy, making hybridization energetically favorable. Consequently, nitrogen\u2019s lone pair adopts an orbital with significant p-character, optimizing bonding and minimizing lone pair\u2013bond pair repulsion.<\/p>\n\n\n\n However, in PH\u2083, AsH\u2083, and SbH\u2083, the central atoms are larger, with their valence electrons occupying higher principal quantum numbers<\/strong> (n = 3, 4, 5<\/em> respectively). These higher orbitals are more diffuse, with larger radial maxima<\/strong>, making orbital overlap less effective. Additionally, as primogenicity<\/strong> suggests, heavier elements tend to avoid hybridization because the energy cost of mixing distant s and p orbitals increases with atomic size. Therefore, the lone pairs in PH\u2083, AsH\u2083, and SbH\u2083 reside primarily in non-hybridized s orbitals with greater s-character.<\/p>\n\n\n\n Thus, nitrogen\u2019s higher Z_eff and lower principal quantum number encourage hybridization and more p-character in the lone pair, while the heavier analogs favor more s-like lone pairs due to poor orbital overlap and energetic constraints.<\/p>\n\n\n\n Rationalize why the lone pair hybrid orbitals for NH3 have less s-character than the lone pair in PH3, AsH3, and SbH3. You must use at least two of the following terms in your rationalization: principal quantum number, Zeff, radial maxima, primogenicity. The Correct Answer and Explanation is: Answer: The lone pair on nitrogen in ammonia […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-232398","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232398","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=232398"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232398\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=232398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=232398"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=232398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner9-276.jpeg\")
<\/figure>\n","protected":false},"excerpt":{"rendered":"