The nuclear radius of 8^O^16 is `3 * 10^-15 metre`. If an atomic mass unit is 1.67*10^-27 kg. Then the nuclear density is approximately?

A neuron having mass 1.67x10^-27 kg and moving at 10^8 m/s collides with a deuteron at rest and stick to it. If the mass of the deuteron is 3.34x10^-27 kg find the speed of the combination

How many electrons (mass 9.1xx10^-31 kg) would balance one Proton (mass 1.67xx10^-27 kg)