In a nuclear reaction, which of the following is conserved
Atomic number
Mass number
Atomic number, mass number and energy
None of these
A nucleus at rest splits into two nuclear parts having same density and the radii in the ratio $1 : 2$ . Their velocities are in ratio ———
Atomic weight of boron is $10.81$ and it has two isotopes $_5{B^{10}}$ and $_5{B^{11}}$. Then ratio of $ _5{B^{10}}{\,:\,_5}{B^{11}} $ in nature would be
Isotopes are atoms having
Which of the following is true for a sample of isotope containing ${U^{235}}$ and ${U^{238}}$
The neutron was discovered by