Question

Which is true in case of the closest approach when $\alpha -$particles are targeted at an atom?

• A. The whole of the kinetic energy of $\alpha -$particles converts into electrostatic potential energy.
• B. The part of the kinetic energy of $\alpha -$particles converts into electrostatic potential energy.
• C. The whole of the kinetic energy of $\alpha -$particles converts into heat energy.
• D. The part of the kinetic energy of $\alpha -$particles converts into electrostatic potential energy and remaining into heat energy.

Answer 1

The correct option is A The whole of the kinetic energy of $\alpha -$particles converts into electrostatic potential energy.

At a certain distance $\left(r_0\right)$ from the nucleus, whole of the kinetic energy of $\alpha -$particles converts into electrostatic potential energy and $\alpha -$particles cannot go further close to the nucleus, this particular distance is called as distance of the closest approach.

Hence, option $\left(A\right)$ is the correct answer.