#### Question

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

#### Solution

It is given that two isotopes of bromine are `""_35^79Br (49.7%)" and """_35^81Br (50.3%)`

Then, the average atomic mass of bromine atom is given by:-

`79xx(49.7/100)+81xx(50.3/100)`

`=3926.3/100+4074.3/100`

`=8000.6/100`

**= 80.006 u**

**= 80 u (approx)**

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Solution If bromine atom is available in the form of, say, two isotopes 79 35Br(49.7%) and 81 35Br(50.3%), calculate the average atomic mass of bromine atom. Concept: Structure of Atom Introduction.