What atom does not have any neutrons?

1 Answer
Nov 5, 2016

The protium #""^1H# isotope.

Explanation:

Most atoms in this universe are this isotope. The nucleus of the #""^1H# isotope contains a single, massive, positively charged particle, and hence its mass #-=# #"1 amu"#.

Of course, deuterium, #""^2H#, and tritium, #""^3H#, isotopes are also known. How many neutrons are found in these atoms?