{"id":221221,"date":"2025-05-29T09:23:32","date_gmt":"2025-05-29T09:23:32","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=221221"},"modified":"2025-05-29T09:23:35","modified_gmt":"2025-05-29T09:23:35","slug":"considering-periodic-trends-valence-electrons-in-which-of-the-following-atoms-experience-the-greatest-effective-nuclear-charge-zeff","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/29\/considering-periodic-trends-valence-electrons-in-which-of-the-following-atoms-experience-the-greatest-effective-nuclear-charge-zeff\/","title":{"rendered":"Considering periodic trends, valence electrons in which of the following atoms experience the greatest effective nuclear charge (Zeff)"},"content":{"rendered":"\n

Considering periodic trends, valence electrons in which of the following atoms experience the greatest effective nuclear charge (Zeff)?<\/p>\n\n\n\n

A) CI
B) C
C) F
D) Ne
E) B<\/p>\n\n\n\n

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

The correct answer is: D) Ne (Neon)<\/strong><\/p>\n\n\n\n

\n\n\n\n

Explanation<\/h3>\n\n\n\n

Effective nuclear charge (Z_eff)<\/strong> is the net positive charge experienced by valence electrons in an atom. It accounts for the attraction from the nucleus and the repulsion from inner (core) electrons. The formula is: Zeff=Z\u2212SZ_{\\text{eff}} = Z – S<\/p>\n\n\n\n

Where:<\/p>\n\n\n\n

    \n
  • ZZ = atomic number (number of protons)<\/li>\n\n\n\n
  • SS = shielding constant (core electron repulsion)<\/li>\n<\/ul>\n\n\n\n

    As we move left to right across a period<\/strong> in the periodic table:<\/p>\n\n\n\n

      \n
    • The atomic number increases<\/strong>, adding more protons to the nucleus.<\/li>\n\n\n\n
    • Electrons are added to the same principal energy level<\/strong>, not increasing shielding significantly.<\/li>\n\n\n\n
    • As a result, Z_eff increases<\/strong> across a period.<\/li>\n<\/ul>\n\n\n\n

      Now, let\u2019s compare the options:<\/p>\n\n\n\n

      Atom<\/th>Atomic Number (Z)<\/th>Electron Configuration<\/th>Z_eff Trend<\/th><\/tr><\/thead>
      B<\/td>5<\/td>1s\u00b2 2s\u00b2 2p\u00b9<\/td>Low<\/td><\/tr>
      C<\/td>6<\/td>1s\u00b2 2s\u00b2 2p\u00b2<\/td>Higher than B<\/td><\/tr>
      F<\/td>9<\/td>1s\u00b2 2s\u00b2 2p\u2075<\/td>Higher than C<\/td><\/tr>
      Ne<\/td>10<\/td>1s\u00b2 2s\u00b2 2p\u2076<\/td>Highest<\/td><\/tr>
      Cl<\/td>17<\/td>1s\u00b2 2s\u00b2 2p\u2076 3s\u00b2 3p\u2075<\/td>Lower than Ne due to added shell (3rd period) which increases shielding<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

      Even though Cl has more protons, its valence electrons are in the third energy level<\/strong>, which is further from the nucleus and more shielded<\/strong>, so they experience a lower Z_eff<\/strong> compared to Ne.<\/p>\n\n\n\n

      Neon, being at the end of Period 2, has:<\/p>\n\n\n\n

        \n
      • 10 protons pulling on its valence electrons.<\/li>\n\n\n\n
      • Minimal shielding by inner electrons (only 1s\u00b2 core).<\/li>\n\n\n\n
      • Electrons in the second shell, close to the nucleus.<\/li>\n<\/ul>\n\n\n\n

        Thus, Neon\u2019s valence electrons experience the greatest effective nuclear charge<\/strong>, making it the correct answer.<\/p>\n\n\n\n

        Answer: D) Ne<\/strong><\/p>\n\n\n\n

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

        Considering periodic trends, valence electrons in which of the following atoms experience the greatest effective nuclear charge (Zeff)? A) CIB) CC) FD) NeE) B The Correct Answer and Explanation is: The correct answer is: D) Ne (Neon) Explanation Effective nuclear charge (Z_eff) is the net positive charge experienced by valence electrons in an atom. It […]<\/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-221221","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/221221","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=221221"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/221221\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=221221"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=221221"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=221221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}