Question

One atom of an element weighs $3.32\times 10^{23}g$. How many number of gram atoms are there in $20kg$ of the element?

• A. $2000$
• B. $20$
• C. $200$
• D. $1000$

Answer 1

Answer: (D)

Atomic mass of an element
= Mass of one atom $\times N_A$
$=3.32\times 10^{23}\times 6.023\times 10^{23}=19.99\approx 20g$
No. of gram atoms
$\frac{\text{Mass of element in grams }}{\text{Atomic mass in grams }}$
$=\frac{20\times 1000}{20}=1000$