Question

The percentage of oxygen in heavy weight is .

• A. 60
• B. 50
• C. 80
• D. $88.9$

Answer 1

Answer: (C)

80

Answer 2

: In $D_{2}O$ percentage of deuterium

$= \frac{4}{20} \times 100 = 20\%$

% of oxygen = 100 – 20 = 80%