Class 9 Chemistry Structure of The Atom Isotopes and Isobars

Isotopes and Isobars

  • Isotopes: - Two nuclei with the same atomic number and different mass number are isotopes of each other.
    • For example: - There are 3 isotopes of carbon(C) having same atomic number 6 but their mass numbers are different i.e. 12, 13 and 14. (126C), (136C), (146C).
    • Each isotope of an element is a pure substance. The chemical properties of isotopes are similar but their physical properties are different.
    • Chlorine occurs in nature in two isotopic forms with masses 35u and 37u in the ratio 3:1.

Applications of Isobars

  1. Isotope of Uranium is used as a fuel in nuclear reactors.
  2. Isotope of Cobalt is used in the treatment of cancer.
  3. Isotope of Iodine is used in the treatment of goitre.
  • Isobars: - The nuclei which have different atomic number but same mass number are known as isobars.
    • For example: - Nitrogen (147N) and Carbon (146C) are both isobars as their mass numbers are same which is 14 but their atomic numbers are 7 and 6 respectively.
    • The total number of nucleons is the same in the atoms of these pairs of elements.


Share these Notes with your friends  

< Prev Next >

You can check our 5-step learning process