Question

An electron in a hydrogen-like atom jumps from an energy level to another energy level in such a way that its kinetic energy changes from ${}^{\prime }{x}^{\prime }$ to $\frac{{}^{\prime }{x}^{\prime }}{4}$. The change in potential energy will be:

• A. $+\frac{3}{2}X$
• B. $-\frac{3}{8}X$
• C. $+\frac{3}{4}X$
• D. $-\frac{3}{4}X$

Answer 1

Answer: (A)

$+\frac{3}{2}X$

The total energy in an orbital is half of its potential energy.

Therefore, $K.E+P.E=\frac{P.E}{2}$

When, $K.E=X$ then $P.E=2X$ and $K.E=\frac{X}{4}$ then $P.E=\frac{X}{2}$.

Therefore, the change in $P.E=\frac{3X}{2}$.

Hence, option A is correct.