Question

The number of neutrons in 1.8 g of water will approximately be

• A. $4.216\times 10^{23}$
• B. $8.432\times 10^{23}$
• C. $4.816\times 10^{23}$
• D. $4.216\times 10^{24}$

Answer 1

Answer: (C)

$H_{2}O=2_1^{1}H{+}_8^{16}O$
$\therefore$ neutrons ${}_0^{1}n=0+8$
${}^n{H}_{2}O=\frac{1.8}{18}=0.1$
Hence ${}_0^{1}n=8\times 0.1\times 6.02\times 10^{23}$
$=4.816\times 10^{23}$