Question

Helium atom is two times heavier than a hydrogen molecule at 298 K, the average kinetic energy of helium is

• A. Two times that of a hydrogen molecule
• B. Same as that of a hydrogen molecule
• C. Four times that of a hydrogen molecule
• D. Half that of a hydrogen molecule

Answer 1

The correct option is B

Same as that of a hydrogen molecule

$\frac{E_{He}}{E_{H_2}}=\sqrt{\frac{T_{H_e}}{T_{H_2}}}$ so energies will be same for

He & $H_2$ at same temperature.