Uranium has atomic number $92$. Two of its common isotopes have nucleon numbers $235$ and $238$. Determine the number of neutrons for these isotopes.

There are seven naturally occurring isotopes of mercury, with nucleon numbers (and relative abundances) of $196 (0.2\%), 198 (10\%), 199 (16.8\%), 200 (23.1\%), 201 (13.2\%), 202 (29.8\%)$ and $204 (6.9\%)$.

(a) Determine the proton and neutron numbers for each isotope.

There are seven naturally occurring isotopes of mercury, with nucleon numbers (and relative abundances) of $196 (0.2\%), 198 (10\%), 199 (16.8\%), 200 (23.1\%), 201 (13.2\%), 202 (29.8\%)$ and $204 (6.9\%)$.

(b) Determine the average relative atomic mass (equivalent to the 'average nucleon number') of naturally occurring mercury.

Eight different atoms are labelled $\mathrm{A}$ to $\mathrm{H}$. Group the elements $\mathrm{A}-\mathrm{H}$ into isotopes and name them using the Periodic Table.

State which of the following forces act between protons and neutrons in a nucleus.

(a) Gravitational

State which of the following forces act between protons and neutrons in a nucleus.

(b) Electrostatic

State which of the following forces act between protons and neutrons in a nucleus.

© Strong nuclear.