{"id":241657,"date":"2025-07-03T19:29:06","date_gmt":"2025-07-03T19:29:06","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=241657"},"modified":"2025-07-03T19:29:08","modified_gmt":"2025-07-03T19:29:08","slug":"an-atom-contains-28-protons-and-31-neutrons","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/03\/an-atom-contains-28-protons-and-31-neutrons\/","title":{"rendered":"An atom contains 28 protons and 31 neutrons"},"content":{"rendered":"\n

An atom contains 28 protons and 31 neutrons Write the symbol for the element this atom represents. What is the atomic mass for this element? How many electrons does this atom contain? Write the nuclide symbol for this atom_ An atom contains 15 electrons and has _ mass number of 31. Write the Symbol for the element this atom represents What is the atomic mass for this element? What is the atomic number for this atom? Write the nuclide Symbol for this atom (2 point) Strontium (Sr) exists in nature as a mixture of the ‘following 4 isotopes: Sr-84 Sr-86 Sr-87 Sr-88 Which of these 4 isotopes i$ most abundant in nature (circle your choice above)? Clearly explain your answer (2 point) Which of the following represent pair of isotopes<\/p>\n\n\n\n

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

Atom with 28 Protons and 31 Neutrons:<\/h3>\n\n\n\n
    \n
  1. Element Symbol<\/strong>: The number of protons in an atom determines the element. An atom with 28 protons is Nickel (Ni)<\/strong>, as the atomic number of Nickel is 28.<\/li>\n\n\n\n
  2. Atomic Mass<\/strong>: The atomic mass of an element is the sum of the number of protons and neutrons. For this atom: Atomic\u00a0Mass=28(Protons)+31(Neutrons)=59\\text{Atomic Mass} = 28 (\\text{Protons}) + 31 (\\text{Neutrons}) = 59Atomic\u00a0Mass=28(Protons)+31(Neutrons)=59 Therefore, the atomic mass is 59 u (atomic mass units)<\/strong>.<\/li>\n\n\n\n
  3. Electrons<\/strong>: In a neutral atom, the number of electrons equals the number of protons. Since this atom has 28 protons, it also contains 28 electrons<\/strong>.<\/li>\n\n\n\n
  4. Nuclide Symbol<\/strong>: The nuclide symbol for this atom can be written as: \\text{^{59}_{28}Ni} This indicates the atomic number (28) and the mass number (59) of the Nickel isotope.<\/li>\n<\/ol>\n\n\n\n
    \n\n\n\n

    Atom with 15 Electrons and Mass Number of 31:<\/h3>\n\n\n\n
      \n
    1. Element Symbol<\/strong>: The number of protons in an atom determines the element. Since this atom has 15 electrons<\/strong>, it must have 15 protons<\/strong> (assuming it is neutral). The element with atomic number 15 is Phosphorus (P)<\/strong>.<\/li>\n\n\n\n
    2. Atomic Mass<\/strong>: The atomic mass of this atom is given as 31<\/strong>, which is the sum of protons and neutrons. Since there are 15 protons, the number of neutrons would be: Neutrons=Atomic\u00a0Mass\u2212Protons=31\u221215=16\\text{Neutrons} = \\text{Atomic Mass} – \\text{Protons} = 31 – 15 = 16Neutrons=Atomic\u00a0Mass\u2212Protons=31\u221215=16 So, this isotope of Phosphorus has 16 neutrons.<\/li>\n\n\n\n
    3. Atomic Number<\/strong>: The atomic number is the number of protons, which is 15<\/strong> for this atom (Phosphorus).<\/li>\n\n\n\n
    4. Nuclide Symbol<\/strong>: The nuclide symbol for this atom is: \\text{^{31}_{15}P} This indicates that this is the isotope of Phosphorus with a mass number of 31.<\/li>\n<\/ol>\n\n\n\n
      \n\n\n\n

      Strontium (Sr) Isotopes:<\/h3>\n\n\n\n

      Strontium exists in nature as a mixture of the following isotopes: Sr-84, Sr-86, Sr-87, and Sr-88<\/strong>. To determine which isotope is most abundant in nature, we consider their relative abundances:<\/p>\n\n\n\n

        \n
      1. Sr-84<\/strong>: Atomic number 38, mass number 84.<\/li>\n\n\n\n
      2. Sr-86<\/strong>: Atomic number 38, mass number 86.<\/li>\n\n\n\n
      3. Sr-87<\/strong>: Atomic number 38, mass number 87.<\/li>\n\n\n\n
      4. Sr-88<\/strong>: Atomic number 38, mass number 88.<\/li>\n<\/ol>\n\n\n\n

        In nature, Sr-88<\/strong> is the most abundant isotope of Strontium. This is because Sr-88<\/strong> makes up about 82.58% of naturally occurring Strontium, while the others are much less abundant. Strontium-88 is stable, whereas the other isotopes are either less stable or have lower natural abundances.<\/p>\n\n\n\n

        \n\n\n\n

        Pair of Isotopes:<\/h3>\n\n\n\n

        Isotopes are atoms of the same element but with different numbers of neutrons. A pair of isotopes would have the same atomic number (same number of protons) but different mass numbers (due to varying numbers of neutrons).<\/p>\n\n\n\n

        For example, Sr-86<\/strong> and Sr-88<\/strong> are a pair of isotopes because both have 38 protons (atomic number 38), but Sr-86<\/strong> has 48 neutrons, and Sr-88<\/strong> has 50 neutrons.<\/p>\n\n\n\n

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

        An atom contains 28 protons and 31 neutrons Write the symbol for the element this atom represents. What is the atomic mass for this element? How many electrons does this atom contain? Write the nuclide symbol for this atom_ An atom contains 15 electrons and has _ mass number of 31. Write the Symbol for […]<\/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-241657","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/241657","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=241657"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/241657\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=241657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=241657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=241657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}