Question

Isotopes of an element has:

• A. Same physical properties
• B. Different chemical properties
• C. Different number of neutrons
• D. Different atomic number

Answer 1

The correct option is C

Different number of neutrons

The correct option is (C).

Explanation of Correct Option:

1. Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons.
2. Isotopes of an element have same atomic number but different mass number.
3. Example: $$\begin{gathered} \mathrm{protium}{\mathrm{H}}_1^1 \\ \mathrm{Deuterium}{\mathrm{H}}_1^2 \\ \mathrm{Tritium}{\mathrm{H}}_1^3 \end{gathered}$$

Explanation of Incorrect Option:

Option (A): Same physical properties

Physical properties are related to atomic mass. Isotopes of an element have different mass number.

Option (B): Different chemical properties

Chemical properties are related to the number of valence electrons. Thus, isotopes have similar chemical properties.

Option (D): Different atomic number

Isotopes of an element have same atomic number but different mass number.

Hence, Isotopes of an element has different number of neutrons.