Question

The radius of a nucleus of mass number 125 is ______.

Options

• 6.0 fm

• 30 fm

• 72 fm

• 150 fm

Answer 1

The radius of a nucleus of mass number 125 is 6.0 fm.

Explanation:

Given: A = 125

R₀ ≈ 1.3 fm

R = 1.3 × 125^1/3

The radius of a nucleus is given by the empirical formula:

R = R₀A^1/3

= 1.3 × (1.3 × 125^1/3)

= 1.3 × 5

= 6.5 fm

Using the commonly accepted approximation R₀ ≈ 1.2 fm:

R = 1.2 × 5

= 6.0 fm