{"id":87113,"date":"2025-06-01T04:29:16","date_gmt":"2025-06-01T04:29:16","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87113"},"modified":"2025-06-01T04:29:16","modified_gmt":"2025-06-01T04:29:16","slug":"which-one-of-the-following-conditions-is-not-correct-for-the-combinati","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/","title":{"rendered":"Which one of the following conditions is not correct for the combinati"},"content":{"rendered":"<p>Which one of the following conditions is not correct for the combination of atomic orbitals to form molecular orbitals ?<\/p>\n<p>[amp_mcq option1=&#8221;The combining atomic orbitals must have same or nearly the same energy.&#8221; option2=&#8221;The combining atomic orbitals must show lateral overlap with each other.&#8221; option3=&#8221;The combining atomic orbitals must have the same symmetry about the molecular axis.&#8221; option4=&#8221;The combining atomic orbitals must overlap to the maximum extent.&#8221; correct=&#8221;option2&#8243;]<\/p>\n<div class=\"psc-box-pyq-exam-year-detail\">\n<div class=\"pyq-exam\">\n<div class=\"psc-heading\">This question was previously asked in<\/div>\n<div class=\"psc-title line-ellipsis\">UPSC Geoscientist &#8211; 2024<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-geoscientist-2024.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-geoscientist-2024\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nThe condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nThe essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are:<br \/>\n1.  **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct)<br \/>\n2.  **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct)<br \/>\n3.  **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct)<br \/>\nStatement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($\\sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($\\pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nSigma bonds are formed by axial overlap (s-s, s-p$_z$, p$_z$-p$_z$ along the internuclear axis). Pi bonds are formed by lateral overlap (p$_x$-p$_x$, p$_y$-p$_y$). A double bond consists of one sigma and one pi bond, while a triple bond consists of one sigma and two pi bonds.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Which one of the following conditions is not correct for the combination of atomic orbitals to form molecular orbitals ? [amp_mcq option1=&#8221;The combining atomic orbitals must have same or nearly the same energy.&#8221; option2=&#8221;The combining atomic orbitals must show lateral overlap with each other.&#8221; option3=&#8221;The combining atomic orbitals must have the same symmetry about the &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Which one of the following conditions is not correct for the combinati\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/#more-87113\">Detailed Solution<span class=\"screen-reader-text\">Which one of the following conditions is not correct for the combinati<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1091],"tags":[1103,1162,1096],"class_list":["post-87113","post","type-post","status-publish","format-standard","hentry","category-upsc-geoscientist","tag-1103","tag-atomic-structure","tag-chemistry","no-featured-image-padding"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v22.2 (Yoast SEO v23.3) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Which one of the following conditions is not correct for the combinati<\/title>\n<meta name=\"description\" content=\"The condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals. The essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are: 1. **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct) 2. **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct) 3. **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct) Statement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Which one of the following conditions is not correct for the combinati\" \/>\n<meta property=\"og:description\" content=\"The condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals. The essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are: 1. **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct) 2. **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct) 3. **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct) Statement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T04:29:16+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"2 minutes\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Which one of the following conditions is not correct for the combinati","description":"The condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals. The essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are: 1. **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct) 2. **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct) 3. **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct) Statement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following conditions is not correct for the combinati","og_description":"The condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals. The essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are: 1. **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct) 2. **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct) 3. **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct) Statement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T04:29:16+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/","name":"Which one of the following conditions is not correct for the combinati","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T04:29:16+00:00","dateModified":"2025-06-01T04:29:16+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The condition that the combining atomic orbitals must show lateral overlap with each other is not correct for the combination of atomic orbitals to form molecular orbitals. The essential conditions for the linear combination of atomic orbitals (LCAO) to form molecular orbitals are: 1. **The combining atomic orbitals must have comparable energies.** This allows for effective interaction and mixing of orbitals. (Statement A is correct) 2. **The combining atomic orbitals must have the same symmetry about the molecular axis.** Orbitals with different symmetries (e.g., s orbital and p$_x$ orbital if the molecular axis is z) cannot effectively overlap. (Statement C is correct) 3. **The combining atomic orbitals must overlap to the maximum possible extent.** Significant overlap leads to strong bonding (and antibonding) molecular orbitals. (Statement D is correct) Statement B claims that combining atomic orbitals *must* show lateral overlap. This is incorrect. Atomic orbitals can overlap axially (end-to-end), which leads to the formation of sigma ($\\sigma$) molecular orbitals, or laterally (side-by-side), which leads to the formation of pi ($\\pi$) molecular orbitals. Both types of overlap are valid and common ways for atomic orbitals to combine. It is not a requirement that *only* lateral overlap must occur. For instance, the formation of H\u2082 molecule involves axial overlap of two 1s orbitals.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-conditions-is-not-correct-for-the-combinati\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC Geoscientist","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-geoscientist\/"},{"@type":"ListItem","position":3,"name":"Which one of the following conditions is not correct for the combinati"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87113","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=87113"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87113\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=87113"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=87113"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=87113"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}