the number of protons in the atomic nucleus
Well basically, light is released when an excited electron returns to a lower energy state. Visible Light is part of the electromagnetic spectrum, and is a kind of radiation emitted.
Molar mass of A l 2 (S O 4 ) 3 = 342.15 g/mol
7.2g/ 342.15 g/mol
you can get number of moles.
then multiply that by12
