How do atomic masses vary throughout the periodic table?

1 Answer
Feb 13, 2014

Atomic masses increase from left to right and from top to bottom of the Periodic Table.

Explanation:

As you go from left to right in the Periodic Table, you are adding more protons and neutrons to the nuclei. The atoms in the rows further down have even more protons and nucleons.

Therefore, atomic mass increases from left to right and from top to bottom of the Periodic Table.