The size of the nucleus is of the order of:

The particle that possesses half-integral spin is:

The coordination number of $Cu$ is

Show that the volume of a nucleus is proportional to its atomic mass number $A$.

$A$ nucleus at rest splits into two nuclear parts having radii in the ratio $1:2$. Their velocities are in the ratio: (in $:1$)

$(a)$ Two stable isotopes of lithium $_{3}^{6} Li$ and $_{3}^{7} Li$ have respective abundances of $7.5 \%$ and $92.5 \%$. These isotopes have masses $6.01512 \; u$ and $7.01600 \; u$,respectively. Find the atomic mass of lithium.
$(b)$ Boron has two stable isotopes,$_{5}^{10} B$ and $_{5}^{11} B$. Their respective masses are $10.01294 \; u$ and $11.00931 \; u$,and the atomic mass of boron is $10.811 \; u$. Find the abundances of $_{5}^{10} B$ and $_{5}^{11} B$.