Question

20 metals of atomic mass which less than 50

Answer 1

Hydrogen : 1 amu
Helium : 4 amu
Lithium : 7 amu

Beryllium : 9 amu

Boron : 11 amu
Carbon : 12 amu
Nitrogen : 14 amu

Oxygen : 16 amu
Fluorine : 19 amu
Neon : 20 amu


Sodium : 23

Magnesium : 24 amu
Aluminum : 27 amu
Silicon : 28 amu
Phosphorus :31 amu
Sulphur : 32 amu
Chlorine : 35 amu
Argon : 39.948(1) amu
Potassium : 39 amu
Calcium : 40 amu

They're are all approximate values.

Hope you got what you want......