What are two atoms of the same element with different mass numbers called?

1 Answer
Dec 13, 2016

Answer:

You speak of #"isotopes......"#

Explanation:

All hydrogen nuclei contain the one proton, the one positively charged, massive nuclear particle. This is the #"protium isotope"#, #""^1H#. A few hydrogen nuclei contain one proton PLUS one neutron, a massive, neutrally charged particle; this is the #"deuterium isotope"#, #""^2H#. And a smaller few hydrogen nuclei contain 2 neutrons, to give the #"tritium isotope"#, #""^3H#.

Most elements have a number of different isotopes, some of them with important nuclear properties. The atomic mass reported on the Periodic Table is the weighted average of the individual, elemental isotopic masses. Capisce?