A gas containing both hydrogen molecules (each molecule contains two hydrogen atoms) and helium atoms has a temperature of 300 K. How does the average speed of the hydrogen molecules compare to the helium atoms?
3 answers
The average speed of the hydrogen molecules is the same as that of the helium atoms.
The average speed of the hydrogen molecules is faster than that of the helium atoms, but it is less than two times faster. Since the temperature is the same for both types of atoms, they have the same average kinetic energy, which is given by K=1/2mv2. Helium is twice as massive as hydrogen, so the average speed of the hydrogen atoms is 2√ times higher than that of the helium atoms.
The average speed of the hydrogen molecules is faster than that of the helium atoms, but it is less than two times faster.