The temperature ,a t which the root mean square velcity of hydrogen molecules equals their escape velocity from the earth, is closed to: [Boltzmann Constant `k_(B)=1.38xx10^(-23)j//K` Avogadro Number `N_(A)=6.02xx10^(26)//Kg` Radius of Earth :`6.4xx10^(6)m` Gravitational acceleration On earth =`10ms^(-2)]`
