Why is the mass of the dihydrogen molecule TWICE that of the hydrogen atom?

1 Answer
Sep 2, 2016

You compare the #H_2# molecule with the #H# atom? Well, there are TWO hydrogen atoms in the molecule, and thus it REASONABLY should have TWICE the mass.


What should the mass of this molecule be compared to the constituent atom? The actual mass of a mole of atoms is given on the Periodic Table.