JEE Main levelNumerical answerDifficulty 2 of 3as027
Take the nuclear radius as R=1.2×10−15A1/3m and the mass of a nucleon as 1.67×10−27kg. Find the density of a nucleus of mass number 64 in units of 1017kgm−3, to two decimals.
Numerical answer type, answer in x 10^17 kg/m^3, tolerance 0.03.
Answer: 2.31 x 10^17 kg/m^3
R = 1.2e-15 x 641/3 = 4.80e-15 m, so volume = (4/3) pi R3 = 4.632e-43 m3. Mass = 64 x 1.67e-27 = 1.069e-25 kg. Density = 2.307e+17 kg/m3 = 2.31 x 1017.