Nuclear forces are

It is now believed that protons and neutrons (which constitute nuclei of ordinary matter) are themselves built out of more elementary units called quarks. $A$ proton and a neutron consist of three quarks each. Two types of quarks,the so-called 'up' quark (denoted by $u$) of charge $+(2/3)e$,and the 'down' quark (denoted by $d$) of charge $-(1/3)e$ together with electrons build up ordinary matter. Suggest a possible quark composition of a proton and neutron.

The ratio of mass densities of nuclei of $^{40}Ca$ and $^{16}O$ is close to

Which of the following is true for a sample of isotopes containing $^{235}U$ and $^{238}U$?

State the dimension of the nucleus from the Rutherford experiment.

Choose the correct statement from the following: