Answer is: nucleus of Cd is 1.26 times greater.
The Nuclear radius formula or radius of nucleus formula: R = R₀ · ∛A.
R is nuclear radius.
R₀ is empirical constant, R₀ = 1.2 10⁻¹⁵ m.
A is number of nucleon.
R(Fe) = 1.2·10⁻¹⁵ m · ∛56.
R(Fe) = 4.59·10⁻¹⁵ m.
R(Cd) = 1.2·10⁻¹⁵ m · ∛112.
R(Cd) = 5.78·10⁻¹⁵ m.
R(Cd) / R(Fe) = 5.78·10⁻¹⁵ m / 4.59·10⁻¹⁵ m.
R(Cd) / R(Fe) = 1.26.
