{"id":233550,"date":"2025-06-13T08:07:20","date_gmt":"2025-06-13T08:07:20","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=233550"},"modified":"2025-06-13T08:07:23","modified_gmt":"2025-06-13T08:07:23","slug":"how-to-calculate-valency-of-an-element-when-atomic-no-is-greater-than-20","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/13\/how-to-calculate-valency-of-an-element-when-atomic-no-is-greater-than-20\/","title":{"rendered":"How to calculate valency of an element when atomic no is greater than 20"},"content":{"rendered":"\n

How to calculate valency of an element when atomic no is greater than 20<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

Valency of Elements with Atomic Number Greater Than 20<\/strong><\/p>\n\n\n\n

To calculate the valency<\/strong> of an element with atomic number greater than 20, one must understand the distribution of electrons in different shells and subshells (electron configuration) and determine how many electrons the atom tends to lose, gain, or share to achieve a stable configuration, typically similar to the nearest noble gas.<\/p>\n\n\n\n

Step-by-Step Calculation:<\/h3>\n\n\n\n
    \n
  1. Write the electron configuration<\/strong> of the element using the Aufbau principle.<\/li>\n\n\n\n
  2. Identify the outermost shell (valence shell)<\/strong> \u2014 this includes the highest principal quantum number (n).<\/li>\n\n\n\n
  3. Determine the number of valence electrons<\/strong> in this outermost shell.<\/li>\n\n\n\n
  4. Calculate the valency<\/strong> based on how many electrons the atom tends to lose, gain, or share to attain a full octet or stable configuration.<\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    Example: Element with Atomic Number 26 (Iron, Fe)<\/h3>\n\n\n\n
      \n
    1. Electron Configuration of Fe (Z = 26):<\/strong>
      1s\u00b2 2s\u00b2 2p\u2076 3s\u00b2 3p\u2076 4s\u00b2 3d\u2076
      Or grouped: [Ar] 4s\u00b2 3d\u2076<\/li>\n\n\n\n
    2. Valence Shell:<\/strong>
      The 4s and 3d electrons are considered in bonding for transition elements. Fe has 2 electrons in the 4s subshell and 6 in the 3d subshell.<\/li>\n\n\n\n
    3. Valency Determination:<\/strong>
      Transition metals may show variable valency. Iron can lose two electrons (4s\u00b2) to form Fe\u00b2\u207a or three electrons (4s\u00b2 and one 3d) to form Fe\u00b3\u207a.
      Therefore, Fe has valencies of 2 and 3<\/strong>.<\/li>\n<\/ol>\n\n\n\n
      \n\n\n\n

      Key Concepts:<\/h3>\n\n\n\n
        \n
      • Valency<\/strong> refers to the combining capacity<\/strong> of an element.<\/li>\n\n\n\n
      • For main group elements<\/strong>, valency is usually equal to the number of electrons required to complete an octet (8 electrons) or duplet (2 electrons for hydrogen and helium).<\/li>\n\n\n\n
      • For transition elements<\/strong> (atomic number > 20), valency may vary due to the involvement of d-orbitals.<\/li>\n\n\n\n
      • Common valency for a transition metal is determined by common oxidation states.<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n

        Conclusion:<\/h3>\n\n\n\n

        For elements with atomic number greater than 20, determining valency requires examining the full electron configuration, especially the d-orbitals for transition metals. These elements often show variable valency<\/strong>, depending on the chemical context and stability of oxidation states.<\/p>\n\n\n\n

        \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

        How to calculate valency of an element when atomic no is greater than 20 The Correct Answer and Explanation is: Valency of Elements with Atomic Number Greater Than 20 To calculate the valency of an element with atomic number greater than 20, one must understand the distribution of electrons in different shells and subshells (electron […]<\/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-233550","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/233550","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=233550"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/233550\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=233550"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=233550"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=233550"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}