Question

Total number of atoms in 20 g of calcium carbonate is ________.

• A. $N_A$
• B. $5N_A$
• C. $\frac{1}{5}{N}_A$
• D. none of the above

Answer 1

The correct option is A $N_A$

number of moles in $20$ g of $CaC{O}_3$

$1$ molecule has $5$ atoms.

$20$ of calcium carbonate has $\Rightarrow \frac{20}{100}\times 5\times N_A$

= $N_A$

Hence, option $A$ is the answer.