Question

Hydrogen atoms have a lower mass than oxygen atoms. If hydrogen molecules and oxygen molecules are at the same temperature, which statement describes the hydrogen atoms according to the equation K = (1/2)mv²?

The hydrogen atoms will have lower average speeds than the oxygen atoms.
The hydrogen atoms will have less kinetic energy than the oxygen atoms.
The hydrogen atoms will have more kinetic energy than the oxygen atoms.
The hydrogen atoms will have higher average speeds than the oxygen atoms.

Answer 1

Hydrogen atoms will have higher average speeds than oxygen atoms at the same temperature because they have lower mass, but their kinetic energies will be the same, as per the principle of equipartition of energy.

Step-by-step explanation:

If hydrogen molecules and oxygen molecules are at the same temperature, according to the equation K = (1/2)mv², the hydrogen atoms will have higher average speeds than the oxygen atoms. This is because at a given temperature, all gases have the same average kinetic energy per molecule (K = KBT), but since hydrogen has a lower mass than oxygen, it must move with a higher speed to have the same kinetic energy. The kinetic energy of the hydrogen and oxygen atoms will be the same because it's determined only by temperature, as long as we are considering ideal gas behavior.