The mass number of nucleus having radius equal to half of the radius of nucleus with mass number 192 is:

We need to find the mass number of a nucleus whose radius is half that of a nucleus with mass number 192.

Nuclear Radius Formula:

$$R = R_0 A^{1/3}$$

where $$R_0 \approx 1.2$$ fm is a constant and $$A$$ is the mass number.

Setting up the equation:

$$R_2 = \frac{R_1}{2}$$, so $$R_0 A_2^{1/3} = \frac{R_0 A_1^{1/3}}{2}$$.

$$A_2^{1/3} = \frac{A_1^{1/3}}{2}$$

Cubing both sides:

$$A_2 = \frac{A_1}{8} = \frac{192}{8} = 24$$

The correct answer is Option 1: 24.