The mass of a molecule of oxygen ( O2 ) is 16 times that of the mass of a molecule of diatomic hydrogen ( H2 ). If the average speed of an oxygen molecule in the air at a temperature of 20 °C is about 500 ms−1 , then the average speed of a diatomic hydrogen molecule in the air at the same temperature is about
a. 30 ms−1 .
b. 125 ms−1 .
c. 2000 ms−1 .
d. 8000 ms−1 .