An unknown nucleus has a nuclear density of 2.29 × 10^17 kg / m^3 and mass of 19.926 × 10^-27 kg. Its mass number A is approximately: (Take R 0=1.2 ×…

An unknown nucleus has a nuclear density of $\displaystyle 2.29 \times 10^{17} \mathrm{~kg} / \mathrm{m}^3$ and mass of $\displaystyle 19.926 \times 10^{-27} \mathrm{~kg}$. Its mass number A is approximately : (Take $\displaystyle \mathrm{R}_0=1.2 \times 10^{-15} \mathrm{~m}, 4 \pi=12.56$ )