Question

The energy absorbed by each molecule ( ${\mathrm{A}}_2$ of a substance is $4.4\times {10}^{-19}\mathrm{J}$) and bond energy per molecule is $4\times {10}^{-19}\mathrm{J}$. The kinetic energy of the molecule per atom will be :

Answer 1

Step 1: Kinetic energy per atom:

• The kinetic energy per atom is defined as the ratio of the difference between energy absorbed and bond energy of a molecule with the total number of atoms in the molecule.
• The formula of kinetic energy per atom is depicted below:

$\mathrm{Kintic}\mathrm{energy}\mathrm{per}\mathrm{atom}=\frac{\mathrm{Energy}\mathrm{absorbed}-\mathrm{Bond}\mathrm{energy}}{\mathrm{No}.\mathrm{of}\mathrm{atoms}\mathrm{in}\mathrm{the}\mathrm{molecule}}$

Step 2: Given Information:

• The energy absorbed by a molecule is $4.4\times {10}^{-19}J$.
• The bond energy of a molecule is $4\times {10}^{-19}J$.

Step 3: Calculation for Kinetic energy per atom:

$\mathrm{Kinetic}\mathrm{energy}\mathrm{per}\mathrm{atom}=\frac{4.4\times {10}^{-19}J-4\times {10}^{-19}J}{2}$

$\mathrm{Kinetic}\mathrm{energy}\mathrm{per}\mathrm{atom}=2\times {10}^{-20}J$

Hence, the kinetic energy of the molecule per atom is $2\times {10}^{-20}J$.