Question

How does the size of a nucleus depend on its mass number? Hence explain why the density of nuclear matter is independent of the size of nucleus.

Answer 1

The radius (size) R of nucleus is related to its mass number (A) as

R = R₀A^1/3 where R₀ = 1.1 × 10^–15 m

If m is the average mass of a nucleon, then mass of nucleus = mA, where A is mass number 

Volume of nucleus

∴ Density of nucleus,

Clearly nuclear density ρ_N is independent of mass number A.