Question

The isotopic abundance of `C-12` and `C-14 "is" 98%` and `2%` respectively. What would be the number of `C-14` isotope in `12 g` carbon sample?
A. `1.2xx10^(22)`
B. `3.01xx10^(23)`
C. `5.88xx10^(23)`
D. `6.02xx10^(23)`

Answer 1

Correct Answer - A
`M_(avg) = 12xx0.98+140.2=12.04`
`n_(C^(12))=(12)/(12.04)=0.996`
Atoms of `C ^(14)=0.996xx(2)/(100)xxN_(A)`
`=0.997xx10^(21)=9.97xx10^(20)`