{"id":205674,"date":"2025-03-25T07:25:47","date_gmt":"2025-03-25T07:25:47","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=205674"},"modified":"2025-03-25T07:25:49","modified_gmt":"2025-03-25T07:25:49","slug":"what-is-the-atomic-mass-of-b-if-19-9-of-all-b-atoms-have-a-mass-of-10-01-amu-and-80-1-have-a-mass-of-11-01-amu-3","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/25\/what-is-the-atomic-mass-of-b-if-19-9-of-all-b-atoms-have-a-mass-of-10-01-amu-and-80-1-have-a-mass-of-11-01-amu-3\/","title":{"rendered":"What is the atomic mass of B if 19.9% of all B atoms have a mass of 10.01 amu and 80.1% have a mass of 11.01 amu"},"content":{"rendered":"\n<p>What is the atomic mass of B if 19.9% of all B atoms have a mass of 10.01 amu and 80.1% have a mass of 11.01 amu?<\/p>\n\n\n\n<p>A) 10.21 amu<\/p>\n\n\n\n<p>B) 10.50 amu<\/p>\n\n\n\n<p>C) 10.63 amu<\/p>\n\n\n\n<p>D) 10.81 amu<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>To calculate the atomic mass of boron (( B )), we use the weighted average formula:<\/p>\n\n\n\n<p>[<br>\\text{Atomic Mass} = (\\% \\text{ abundance of isotope 1} \\times \\text{mass of isotope 1}) + (\\% \\text{ abundance of isotope 2} \\times \\text{mass of isotope 2})<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Given Data:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Isotope 1<\/strong>: Mass = <strong>10.01 amu<\/strong>, Abundance = <strong>19.9%<\/strong> (<strong>0.199<\/strong> in decimal form)<\/li>\n\n\n\n<li><strong>Isotope 2<\/strong>: Mass = <strong>11.01 amu<\/strong>, Abundance = <strong>80.1%<\/strong> (<strong>0.801<\/strong> in decimal form)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Calculation:<\/h3>\n\n\n\n<p>[<br>\\text{Atomic Mass} = (0.199 \\times 10.01) + (0.801 \\times 11.01)<br>]<\/p>\n\n\n\n<p>[<br>= 1.990 + 8.821<br>]<\/p>\n\n\n\n<p>[<br>= 10.811 \\text{ amu}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Correct Answer:<\/h3>\n\n\n\n<p><strong>D) 10.81 amu<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>The atomic mass of an element is calculated as the weighted average of its isotopes based on their natural abundance. Since boron has two stable isotopes, <strong>(^{10}B)<\/strong> and <strong>(^{11}B)<\/strong>, we multiply the mass of each isotope by its respective fractional abundance and sum the results.<\/p>\n\n\n\n<p>In this case, <strong>(^{11}B)<\/strong> has a much higher abundance (80.1%) compared to <strong>(^{10}B)<\/strong> (19.9%), which means the atomic mass of boron is closer to <strong>11.01 amu<\/strong> than <strong>10.01 amu<\/strong>. The computed result of <strong>10.81 amu<\/strong> aligns with the periodic table value.<\/p>\n\n\n\n<p>This approach ensures an accurate representation of boron&#8217;s atomic mass as found in nature.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/03\/image-1382.png\" alt=\"\" class=\"wp-image-205675\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>What is the atomic mass of B if 19.9% of all B atoms have a mass of 10.01 amu and 80.1% have a mass of 11.01 amu? A) 10.21 amu B) 10.50 amu C) 10.63 amu D) 10.81 amu The correct answer and explanation is : To calculate the atomic mass of boron (( B [&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-205674","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/205674","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=205674"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/205674\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=205674"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=205674"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=205674"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}