Question

The energy absorbed by each molecule $\left(A_{2}\right)$ of a substance is $4.4 \times 10^{-19} J$ and bond energy per molecule is $4.0 \times 10^{-19} J$. The kinetic energy of the molecule per atom will be

• A. $2.2 \times 10^{-19} J$
• B. $2.0 \times 10^{-19} J$
• C. $4.0 \times 10^{-20} J$
• D. $2.0 \times 10^{-20} J$

Answer 1

Answer: (D)

Energy absorbed by each molecule $=4.4 \times 10^{-19} J$

Energy required to break the bond $=4.0 \times 10^{-19} J$

Remaining energy gets converted to kinetic energ

$=\left(4.4 \times 10^{-19}-4.0 \times 10^{-19}\right) J$

$=0.4 \times 10^{-19} J$ per molecule

$\therefore $ Kinetic energy per atom $=0.2 \times 10^{-19} J =2 \times 10^{-20} J$