2. Questions Bank
  3. 9th Class
  4. Science
  5. Structure of the Atom

9th Class Science Structure of the Atom Question Bank Structure of Atom

  • question_answer
    There are three isotopes of carbon which are named as C-12, C-13 and C-14 out of which C-12 is the most abundant isotope. In the given structures of three isotopes, what will be the composition of the nucleus?

    A) C -12 : 6p + 6n, C - 13 : 7p + 6n, C - 14 : 8p + 6n

    B) C - 12 : 6p + 6n, C -13 : 6p + 7n, C - 14 : 6p + 8n

    C) C - 12 : 6p + 6n, C - 13 : 5p + 8n, C - 14 : 7p + 7n

    D) C - 12 : 6p + 6n, C - 13 : 12p +1n, C - 14 : 5p + 9n

    Correct Answer: B

    Solution :

    Isotopes are the atoms of the same element, having same atomic number but different mass numbers. For a neutral atom, Atomic number = Number of protons                         = Number of electrons Mass number = Number of protons                         + Number of neutrons. As the mass number of isotopes are 12, 13 and 14 so, number of neutrons will be \[12-6=6,\text{ }13-6=7\] and \[14-6=8\] in C-12, C-13 and C-14 respectively.


You need to login to perform this action.
You will be redirected in 3 sec spinner