# How many neutrons does a standard hydrogen atom have in its nucleus?

May 21, 2016

#### Explanation:

The protium isotope, ""^1H, has only the $1$ massive, positively charged particle in its nucleus. Protium has an isotopic abundance of over 99%. A smaller percentage of hydrogen nuclei have 1 neutron in the nucleus to give $\text{deuterium}$, ""^2H. An even smaller percentage is expressed by the $\text{tritium}$ isotope, ""^3H.

So called deuterium and tritium labels can be introduced into organic compounds relatively easily, the which allows specific and sensitive probes of structure and reactivity.