Question

What is the average atomic mass of chlorine if it has isotopes of masses 36.96590 and 34.96885, which are 24.47% and 75.53% abundant, respectively?

Answer 1

The average atomic mass of the given sample of chlorine is `"35.46 u"`.

Explanation:

Change the percentages to their decimal forms:

`24.47%=24.47/100=0.2447`

`75.53%=75.53/100=0.7553`

Multiply the mass of each isotope by its percent abundance and add. The symbol `"u"` is used for atomic mass units.

`"0.2447(36.9590 u)+0.7553(34.96885 u)"="35.46 u"`

Answer 2

`35.4573`

Explanation:

The average mass is summation of the percentages of each mass multiplied by that mass.
`(36.9650 xx 0.2447) + (34.96885 xx 0.7553) = 35.4573`