The energy absorbed by each molecule ( `A_(2)` ) of a subtance is `4.4 xx 10^(-19) J` and bond energy per molecule is `4 xx 10^(-19)`J. The kinetic energy of the molecule per atom will be

Options

A. `2.2 xx 10^(-19) J`
B. `2.0 xx 10^(-19) J`
C. `4.0 xx 10^(-20) J`
D. ` 2.0 xx 10^(-20)J`

Answer

D

Explanation

Kinetic enerlgy of the molecule
`= 4.4 xx 10^(-19) - 4.0 xx 10^(-19) J`
`= 0.4 xx 10^(-19) `J per molecule
Kinetic energy per atom `= ( 0.4 xx 10^(-19) ) //2 `
`= 0.2 xx 10^(-19) J = 2 xx 10^(-20) J`