Question

As the orbit number increases, the K.E and P.E of an electron:
(A) both increase
(B) both decrease
(C) K.E increases but P.E decreases
(D) P.E increases but K.E decreases

Answer 1

Hint : In order to answer this question, to know what happens with the kinetic and potential energies when orbit number increases, we will explain the whole reason or phenomenon that affects the kinetic and the potential energies.

Complete Step By Step Answer:
As we know that- according to Bohr’s atomic model,
The expression of P.E and K.E is given by-
 $ \because P.E = \dfrac{{ - K{z^2}{e^2}}}{{{n^2}}} $
where, $ P.E\alpha \dfrac{{ - 1}}{{{n^2}}} $
and,
 $ K.E = \dfrac{{K{z^2}{e^2}}}{{2{n^2}}} $
where, $ K.E\alpha \dfrac{1}{{{n^2}}} $
In the both expression, $ n $ is the orbit number
and, $ z $ is the atomic number.
Clearly, on increasing the orbit number, $ n $ , P.E will increase and K.E will decrease.
We must apply force to accelerate an item. We must work in order to exert force. Energy is transferred when work is done on an object, and the object moves at a new constant speed. Kinetic energy is the energy that is transported and is determined by the mass and speed reached.
Whereas, Potential energy is created in systems where parts exert forces on one another that are proportional to their configuration, or relative position. The force of gravity between the Earth and the ball depends only on the distance between them in the Earth-ball system.
Hence, the correct option is (D) P.E increases but K.E decreases.

Note :
An object's potential energy cannot be transmitted to another entity – you can't suck the potential energy out of a skyscraper's apple. Kinetic energy can be transferred, as evidenced by the kinetic energy of a falling apple injuring a car or striking a bird.