The energy absorbed by each molecule ($A_2$) of a substance is $4.4\times 10^{-19}\text{J}$ and bond energy per molecule is $4.0\times 10^{-19}\text{J}$. The kinetic energy of the molecule per atom will be:

1. Total energy absorbed = $4.4\times 10^{-19}\text{J}$.2. Energy used to break the bond = $4.0\times 10^{-19}\text{J}$.3. Remaining energy becomes the kinetic energy of the two resulting atoms:
$${\text{KE}}_{\text{total}}=4.4\times 10^{-19}-4.0\times 10^{-19}=0.4\times 10^{-19}\text{J}$$
4. Since the molecule $A_2$ produces two atoms, the kinetic energy per atom is:
$${\text{KE}}_{\text{atom}}=\frac{0.4\times 10^{-19}}{2}=0.2\times 10^{-19}=2.0\times 10^{-20}\text{J}$$