Which of the following is a property of isotopes of an element?

(i) They have the same atomic mass.

(ii) They have the same atomic number.

(iii) They exhibit different physical properties.

(iv) They exhibit similar chemical properties.

  1. (ii) and (iii)
  2. (ii), (iii) and (iv)
  3. (ii) and (iv)
  4. (i), (iii) and (iv)
Option 2 :(ii), (iii) and (iv)

Correct Answer: Option 2 :(ii), (iii) and (iv)

Key Points

  • Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons.
  • All isotopes of an element share the same atomic number, which defines the element itself.
  • Isotopes have different atomic masses due to the differing number of neutrons.
  • They exhibit similar chemical properties because they have the same electronic configuration.
  • However, isotopes can exhibit different physical properties, such as density and melting points, due to variations in mass.

Why Other Options Are Wrong

  • Option 1 (ii) and (iii): While it correctly identifies that isotopes have the same atomic number and can exhibit different physical properties, it omits the fact that they also exhibit similar chemical properties.
  • Option 3 (ii) and (iv): This option acknowledges that isotopes have the same atomic number and exhibit similar chemical properties, but it fails to mention the differences in physical properties.
  • Option 4 (i), (iii) and (iv): This choice incorrectly states that isotopes have the same atomic mass, which is not true as they differ in mass due to the number of neutrons.

Quick Tip for Exam

When studying isotopes, remember that they share the same atomic number and exhibit similar chemical properties, but differ in physical properties due to their varying atomic masses. This distinction is crucial for answering questions related to isotopes accurately.

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