{"id":200976,"date":"2025-03-14T08:52:44","date_gmt":"2025-03-14T08:52:44","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=200976"},"modified":"2025-03-14T08:52:46","modified_gmt":"2025-03-14T08:52:46","slug":"the-ground-state-electron-configuration-of-_____is-ar4s13d5","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/14\/the-ground-state-electron-configuration-of-_____is-ar4s13d5\/","title":{"rendered":"The ground-state electron configuration of _____is [Ar]4s13d5"},"content":{"rendered":"\n<p>The ground-state electron configuration of _____is [Ar]4s13d5.<br>A) V<br>B) Mn<br>C) Fe<br>D) Cr<br>E) K<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>The correct answer is <strong>D) Cr (Chromium)<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>The electron configuration of an atom describes how the electrons are distributed in its atomic orbitals. To determine the ground-state electron configuration of an element, we use the Aufbau principle, the Pauli exclusion principle, and Hund&#8217;s rule, which tell us how electrons fill orbitals in order of increasing energy.<\/p>\n\n\n\n<p>The elements given in the options are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>A) V (Vanadium)<\/strong>: Atomic number 23<\/li>\n\n\n\n<li><strong>B) Mn (Manganese)<\/strong>: Atomic number 25<\/li>\n\n\n\n<li><strong>C) Fe (Iron)<\/strong>: Atomic number 26<\/li>\n\n\n\n<li><strong>D) Cr (Chromium)<\/strong>: Atomic number 24<\/li>\n\n\n\n<li><strong>E) K (Potassium)<\/strong>: Atomic number 19<\/li>\n<\/ul>\n\n\n\n<p>Now, let\u2019s break down the electron configurations for each element.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Chromium (Cr) \u2013 Atomic Number 24<\/h3>\n\n\n\n<p>The expected electron configuration for Chromium (Cr), without considering exceptions, would be:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>1s\u00b2 2s\u00b2 2p\u2076 3s\u00b2 3p\u2076 3d\u00b9\u2070 4s\u00b2 3d\u2074 (this is based on the Aufbau principle)<\/li>\n<\/ul>\n\n\n\n<p>However, there is an exception to the expected configuration. Chromium (Cr) prefers to have a half-filled d-subshell, which provides additional stability. To achieve this, one electron from the 4s orbital is promoted to the 3d orbital. As a result, the ground-state electron configuration for Chromium is:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>[Ar] 4s\u00b9 3d\u2075<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This gives Chromium a configuration of <strong>[Ar] 4s\u00b9 3d\u2075<\/strong>, where the 4s orbital has one electron, and the 3d orbital has five electrons, fully occupying the d-subshell. This configuration is more stable because the d-subshell is half-filled.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Why is this configuration important?<\/h3>\n\n\n\n<p>This half-filled d-subshell configuration provides added stability due to the symmetry and exchange energy associated with a half-filled set of degenerate orbitals. For many transition metals, configurations that lead to a stable d-subshell (such as half-filled or fully-filled) are more favorable energetically than those that do not follow this rule.<\/p>\n\n\n\n<p>Thus, the ground-state electron configuration of Chromium (Cr) is <strong>[Ar] 4s\u00b9 3d\u2075<\/strong>, which is consistent with option <strong>D)<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The ground-state electron configuration of _____is [Ar]4s13d5.A) VB) MnC) FeD) CrE) K The correct answer and explanation is : The correct answer is D) Cr (Chromium). Explanation: The electron configuration of an atom describes how the electrons are distributed in its atomic orbitals. To determine the ground-state electron configuration of an element, we use the [&hellip;]<\/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-200976","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/200976","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=200976"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/200976\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=200976"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=200976"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=200976"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}