Question

The weight of a single atom of oxygen is :

• A. $ 0.057\times 10^{23}g $
• B. $ 2.657\times 10^{-23}g $
• C. $ 2.657\times 10^{23}g $
• D. $ 4.657\times 10^{-23}g $

Answer 1

Answer: (B)

Atomic mass $=$ Avogadro number
$6.023 \times 10^{23}$ atoms of $O_{2}$ is present in $=16 \,g$
$\therefore \,1$ atoms of $O_{2}$ is present in
$=\frac{16}{6.023 \times 10^{23}}$
$=2.66 \times 10^{-23} g$