Which of the following is not made by quarks?

As compared to a $^{12}C$ atom,a $^{14}C$ atom has:

In a periodic table,the average atomic mass of magnesium is given as $24.312 \; u$. This average value is based on their relative natural abundance on Earth. The three isotopes and their masses are $_{12}^{24} Mg \; (23.98504 \; u)$,$_{12}^{25} Mg \; (24.98584 \; u)$,and $_{12}^{26} Mg \; (25.98259 \; u)$. The natural abundance of $_{12}^{24} Mg$ is $78.99 \%$. Calculate the abundances of the other two isotopes.

The mass number of an iodine nucleus and a polonium nucleus is $125$ and $216$ respectively. The ratio of the radius of the iodine nucleus to that of the polonium nucleus is:

Mark the correct statement.

The surface areas of two nuclei are in the ratio $9: 25$. The mass numbers of the nuclei are in the ratio