1.
Consider a nucleus 30X^{30}\text{X}. Its approximate density is (Take 1amu=1.6×1027kg1\,\text{amu} = 1.6 \times 10^{-27}\,\text{kg}, R0=1.2×1015mR_0 = 1.2 \times 10^{-15}\,\text{m})