How do you calculate the atomic number of an isotope?

1 Answer
Apr 23, 2016

Answer:

Atomic number #Z#, is a given. The atomic numbers of isotopes are the same.

Explanation:

The number of protons, positively charged nuclear particles, determines the the identity of the element: #Z=1, H#; #Z=2, He#; #Z=3, Li#; etc.

On the other hand, a given element can have different numbers of neutrons, neutrally charged nuclear particles, and this difference gives rise to the existence of isotopes.

For hydrogen, for instance, #""^1H#, the protium isotope (1 proton only in the nucleus), #""^2H#, the deuterium isotope (a proton and a neutron in the nucleus) #""^3H#, (a proton and 2 neutrons) the tritium isotope. These are all hydrogen atoms because they have the 1 proton in their nucleus, and are more or less the same chemically. Most elements have one or more isotopes. As #Z# increases the range of isotopes becomes greater.