<Dd> = 4 π (m 2 π k T) 3 2 3 8 π 1 2 (2 k T m) 5 2 (\ displaystyle = (\ sqrt (4 \ pi \ left ((\ frac (m) (2 \ pi kT)) \ right) ^ (\ frac (3) (2)) (\ frac (3) (8)) \ pi ^ (\ frac (1) (2)) \ left ((\ frac (2kT) (m)) \ right) ^ (\ frac (5) (2)))) \, \!) </Dd> <Dd> = 3 k T m (\ displaystyle = (\ sqrt (\ frac (3kT) (m)))) </Dd>

Root mean square speed of a hydrogen molecule