The temperature, at which the root mean square
velocity of hydrogen molecules equals their
escape velocity from the earth, is closest to :
[Boltzmann Constant k_B = 1.38 × 10^–23 J/K
Avogadro Number N_A = 6.02 × 10²⁶ /kg
Radius of Earth : 6.4 × 10⁶ m
Gravitational acceleration on Earth = 10ms^–2]