The energy absorbed by each molecule $\left(A_2\right)$ of a substance is $4.4 \times 10^{-19} \mathrm{~J}$…
The energy absorbed by each molecule $\left(A_2\right)$ of a substance is $4.4 \times 10^{-19} \mathrm{~J}$ and bond energy per molecule is $4.0 \times 10^{-19} \mathrm{~J}$. The kinetic energy of the molecule per atom will be
$2.0 \times 10^{-20} \mathrm{~J}$
$2.2 \times 10^{-19} \mathrm{~J}$
$2.0 \times 10^{-19} \mathrm{~J}$
$4.0 \times 10^{-20} \mathrm{~J}$
Solution
$K E$ of molecule $=$ energy absorbed by molecule
- BE per molecule
$\begin{aligned}
& =\left[\left(4.4 \times 10^{-19}\right)-\left(4.0 \times 10^{-19}\right) \mathrm{J}\right. \\
& =0.4 \times 10^{-19} \mathrm{~J} \\
& \text { KE per atom }=\frac{0.4 \times 10^{-19}}{2} \mathrm{~J}=2.0 \times 10^{-20} \mathrm{~J}
\end{aligned}$