# What is a particle inside an atom that does not carry an electrical charge?

$\text{A neutron.....................}$
Since the number of protons determines the identity of the element, the number of neutrons determines the isotope. Most hydrogen nuclei have the 1 proton present in their nucleus to give the $\text{protium isotope}$, ""^1H. A few hydrogen nuclei have 1 proton and 1 neutron present in their nucleus to give the $\text{deuterium isotope}$, ""^2H. And a smaller few hydrogen nuclei have 1 proton and 2 neutrons present in their nucleus to give the $\text{tritium isotope}$, ""^3H. How many electrons does each isotope have?