{"id":93130,"date":"2025-06-01T11:42:27","date_gmt":"2025-06-01T11:42:27","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=93130"},"modified":"2025-06-01T11:42:27","modified_gmt":"2025-06-01T11:42:27","slug":"the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/","title":{"rendered":"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen"},"content":{"rendered":"<p>The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen (N\u2082). The composition of O\u2082 and N\u2082 is approximately :<\/p>\n<p>[amp_mcq option1=&#8221;29% and 70% respectively.&#8221; option2=&#8221;19% and 80% respectively.&#8221; option3=&#8221;21% and 78% respectively.&#8221; option4=&#8221;23% and 76% respectively.&#8221; correct=&#8221;option3&#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 CISF-AC-EXE &#8211; 2022<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-cisf-ac-exe-2022.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-cisf-ac-exe-2022\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nThe Earth&#8217;s atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082).<br \/>\nThe approximate composition of dry atmospheric air by volume is:<br \/>\nNitrogen (N\u2082) \u2248 78.09%<br \/>\nOxygen (O\u2082) \u2248 20.95%<br \/>\nArgon (Ar) \u2248 0.93%<br \/>\nCarbon Dioxide (CO\u2082) \u2248 0.04%<br \/>\nTrace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition.<\/p>\n<p>Looking at the options for the composition of O\u2082 and N\u2082:<br \/>\nA) 29% O\u2082, 70% N\u2082<br \/>\nB) 19% O\u2082, 80% N\u2082<br \/>\nC) 21% O\u2082, 78% N\u2082<br \/>\nD) 23% O\u2082, 76% N\u2082<\/p>\n<p>Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\n&#8211; Atmospheric air is a mixture of gases.<br \/>\n&#8211; The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082).<br \/>\n&#8211; Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nWhile Nitrogen and Oxygen make up the vast majority of the atmosphere (about 99%), the remaining 1% includes important gases like Argon, which is the third most abundant gas, and Carbon Dioxide, which plays a significant role in the greenhouse effect, despite its small concentration. These percentages can be taught as roughly 4\/5th Nitrogen and 1\/5th Oxygen for simplification, but 78% and 21% are more accurate approximate figures often cited.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen (N\u2082). The composition of O\u2082 and N\u2082 is approximately : [amp_mcq option1=&#8221;29% and 70% respectively.&#8221; option2=&#8221;19% and 80% respectively.&#8221; option3=&#8221;21% and 78% respectively.&#8221; option4=&#8221;23% and 76% respectively.&#8221; correct=&#8221;option3&#8243;] This question was previously asked in UPSC CISF-AC-EXE &#8211; 2022 Download PDFAttempt Online The Earth&#8217;s atmosphere &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/#more-93130\">Detailed Solution<span class=\"screen-reader-text\">The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen<\/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":[1089],"tags":[1108,1096,1239],"class_list":["post-93130","post","type-post","status-publish","format-standard","hentry","category-upsc-cisf-ac-exe","tag-1108","tag-chemistry","tag-inorganic-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>The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen<\/title>\n<meta name=\"description\" content=\"The Earth&#039;s atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082). The approximate composition of dry atmospheric air by volume is: Nitrogen (N\u2082) \u2248 78.09% Oxygen (O\u2082) \u2248 20.95% Argon (Ar) \u2248 0.93% Carbon Dioxide (CO\u2082) \u2248 0.04% Trace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition. Looking at the options for the composition of O\u2082 and N\u2082: A) 29% O\u2082, 70% N\u2082 B) 19% O\u2082, 80% N\u2082 C) 21% O\u2082, 78% N\u2082 D) 23% O\u2082, 76% N\u2082 Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation. - Atmospheric air is a mixture of gases. - The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082). - Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.\" \/>\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\/the-main-constituents-of-atmospheric-air-are-oxygen-o\u2082-and-nitrogen\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen\" \/>\n<meta property=\"og:description\" content=\"The Earth&#039;s atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082). The approximate composition of dry atmospheric air by volume is: Nitrogen (N\u2082) \u2248 78.09% Oxygen (O\u2082) \u2248 20.95% Argon (Ar) \u2248 0.93% Carbon Dioxide (CO\u2082) \u2248 0.04% Trace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition. Looking at the options for the composition of O\u2082 and N\u2082: A) 29% O\u2082, 70% N\u2082 B) 19% O\u2082, 80% N\u2082 C) 21% O\u2082, 78% N\u2082 D) 23% O\u2082, 76% N\u2082 Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation. - Atmospheric air is a mixture of gases. - The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082). - Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o\u2082-and-nitrogen\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T11:42:27+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=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen","description":"The Earth's atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082). The approximate composition of dry atmospheric air by volume is: Nitrogen (N\u2082) \u2248 78.09% Oxygen (O\u2082) \u2248 20.95% Argon (Ar) \u2248 0.93% Carbon Dioxide (CO\u2082) \u2248 0.04% Trace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition. Looking at the options for the composition of O\u2082 and N\u2082: A) 29% O\u2082, 70% N\u2082 B) 19% O\u2082, 80% N\u2082 C) 21% O\u2082, 78% N\u2082 D) 23% O\u2082, 76% N\u2082 Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation. - Atmospheric air is a mixture of gases. - The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082). - Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.","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\/the-main-constituents-of-atmospheric-air-are-oxygen-o\u2082-and-nitrogen\/","og_locale":"en_US","og_type":"article","og_title":"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen","og_description":"The Earth's atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082). The approximate composition of dry atmospheric air by volume is: Nitrogen (N\u2082) \u2248 78.09% Oxygen (O\u2082) \u2248 20.95% Argon (Ar) \u2248 0.93% Carbon Dioxide (CO\u2082) \u2248 0.04% Trace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition. Looking at the options for the composition of O\u2082 and N\u2082: A) 29% O\u2082, 70% N\u2082 B) 19% O\u2082, 80% N\u2082 C) 21% O\u2082, 78% N\u2082 D) 23% O\u2082, 76% N\u2082 Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation. - Atmospheric air is a mixture of gases. - The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082). - Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o\u2082-and-nitrogen\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T11:42:27+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/","url":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/","name":"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T11:42:27+00:00","dateModified":"2025-06-01T11:42:27+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The Earth's atmosphere is primarily a mixture of gases. The two most abundant gases in dry atmospheric air are Nitrogen (N\u2082) and Oxygen (O\u2082). The approximate composition of dry atmospheric air by volume is: Nitrogen (N\u2082) \u2248 78.09% Oxygen (O\u2082) \u2248 20.95% Argon (Ar) \u2248 0.93% Carbon Dioxide (CO\u2082) \u2248 0.04% Trace gases (Neon, Helium, Methane, Krypton, Hydrogen, etc.) make up the rest. Water vapor is also present, but its concentration varies significantly depending on location and weather. The question likely refers to dry air composition. Looking at the options for the composition of O\u2082 and N\u2082: A) 29% O\u2082, 70% N\u2082 B) 19% O\u2082, 80% N\u2082 C) 21% O\u2082, 78% N\u2082 D) 23% O\u2082, 76% N\u2082 Comparing these options to the actual percentages (\u224820.95% O\u2082 and \u224878.09% N\u2082), option C (21% and 78%) is the closest approximation. - Atmospheric air is a mixture of gases. - The main constituents are Nitrogen (N\u2082) and Oxygen (O\u2082). - Their approximate percentages by volume are about 78% Nitrogen and 21% Oxygen.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-main-constituents-of-atmospheric-air-are-oxygen-o%e2%82%82-and-nitrogen\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CISF-AC-EXE","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cisf-ac-exe\/"},{"@type":"ListItem","position":3,"name":"The main constituents of atmospheric air are Oxygen (O\u2082) and Nitrogen"}]},{"@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\/93130","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=93130"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/93130\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=93130"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=93130"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=93130"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}