At what temperature the kinetic energy of a gas molecule is one-half of its value at `30^@C`?

Explanation

`(K.E.) =3/2 KT`
At two different conditions ` ((KE)_1)/((KE)_2) = (T_1) /(T_2) , (1)/( 1//2) = ( 303)/(T_2)`
Temperature at which kinetic energy is half =`(303)/(2)`
` = 151.5 K =- 121.5^@ C `