If bromine atom is in the form of say isotopes `"_35^79Br` (49.7%) and `"_35^81Br` (50.3%) then calculate the average mass of bromine atom.

Explanation

Average atomic mass of bromine atom
`= (79 xx (49.7)/(100) + 81 xx (50.3)/(100))u`
`= (39.263 + 40.743)u`
= 80.006 u
= 80.0 u