{"id":232262,"date":"2025-06-11T22:07:17","date_gmt":"2025-06-11T22:07:17","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=232262"},"modified":"2025-06-11T22:07:18","modified_gmt":"2025-06-11T22:07:18","slug":"the-electron-configuration-of-calcium-ion-ca1-has-its-atomic-number-20","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/11\/the-electron-configuration-of-calcium-ion-ca1-has-its-atomic-number-20\/","title":{"rendered":"The electron configuration of calcium ion (Ca+1) has its atomic number 20."},"content":{"rendered":"\n<pre id=\"preorder-ask-header-text\" class=\"wp-block-preformatted\">The electron configuration of calcium ion (Ca+1) has its atomic number 20. It has 2 unpaired electrons and is paramagnetic.<\/pre>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-0-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p><strong>Correct Answer:<\/strong><br>The electron configuration of a calcium ion with a +1 charge (Ca\u207a) is:<br><strong>[Ar] 4s\u00b9<\/strong><\/p>\n\n\n\n<p>Ca\u207a has <strong>1 unpaired electron<\/strong> and is <strong>paramagnetic<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>Calcium (Ca) is an alkaline earth metal with atomic number 20. In its neutral (uncharged) state, the electron configuration of calcium is:<br><strong>Ca: 1s\u00b2 2s\u00b2 2p\u2076 3s\u00b2 3p\u2076 4s\u00b2<\/strong><br>or, using noble gas shorthand:<br><strong>[Ar] 4s\u00b2<\/strong><\/p>\n\n\n\n<p>This configuration reflects the filling of electrons according to the Aufbau principle, Hund\u2019s rule, and the Pauli exclusion principle. The two electrons in the outermost 4s orbital are the valence electrons and are the most loosely bound.<\/p>\n\n\n\n<p>When calcium loses <strong>one electron<\/strong> to form a <strong>Ca\u207a<\/strong> ion (not the common +2 oxidation state), the electron is removed from the <strong>4s orbital<\/strong>, which is the highest energy orbital in the atom.<\/p>\n\n\n\n<p>Thus, the electron configuration of Ca\u207a becomes:<br><strong>[Ar] 4s\u00b9<\/strong><\/p>\n\n\n\n<p>The <strong>4s\u00b9<\/strong> configuration has <strong>one unpaired electron<\/strong>, since there is a single electron in the 4s orbital without a partner of opposite spin.<\/p>\n\n\n\n<p>Because of this unpaired electron, the Ca\u207a ion is <strong>paramagnetic<\/strong>. Paramagnetism refers to the tendency of species with unpaired electrons to be attracted to a magnetic field. Unpaired electrons generate a magnetic moment, and the ion interacts with external magnetic fields.<\/p>\n\n\n\n<p>In contrast, a Ca\u00b2\u207a ion (which is the more stable and commonly occurring form in nature) has the configuration <strong>[Ar]<\/strong>, with no unpaired electrons, making it <strong>diamagnetic<\/strong>.<\/p>\n\n\n\n<p>Therefore, Ca\u207a with its [Ar] 4s\u00b9 configuration has <strong>1 unpaired electron<\/strong> and exhibits <strong>paramagnetic<\/strong> behavior due to the presence of that unpaired electron<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-324.jpeg\" alt=\"\" class=\"wp-image-232263\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>The electron configuration of calcium ion (Ca+1) has its atomic number 20. It has 2 unpaired electrons and is paramagnetic. The Correct Answer and Explanation is: Correct Answer:The electron configuration of a calcium ion with a +1 charge (Ca\u207a) is:[Ar] 4s\u00b9 Ca\u207a has 1 unpaired electron and is paramagnetic. Explanation: Calcium (Ca) is an alkaline [&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-232262","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232262","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=232262"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232262\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=232262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=232262"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=232262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}