Question

If isotopic distribution of C-12 and C-14 is 98% and 2% respectively, then the number of C-14 atoms in 12 g of carbon is

• A. $1.032\times10^{22}$
• B. $3.01\times10^{22}$
• C. $5.88\times10^{23}$
• D. $6.02\times10^{23}$

Answer 1

Answer: (A)

$1.032\times10^{22}$

Answer 2

In $12\, g$ of carbon, the amount of $C - 14$ $=12\times 2 /100=0.24\,g$ $\therefore C-14$ atoms in $0.24\,g=\frac{0.24\times6.02\times10^{23}}{14}$ $=1.03\times10^{22}$ atoms