Which element in period 2 has the smallest atomic mass?

1 Answer
Sep 10, 2016

Lithium

Explanation:

If you are doing your chemistry homework, you certainly should have a Periodic Table in front of you.

The second Period begins with lithium, whose atomic mass is #"6.94 g"*"mol"^-1#.

it ends with neon, whose atomic mass is #"20.18 g"*"mol"^-1#.