Question

Calculate the change in its potential energy of an electron in an atom which jumps in such a way that its kinetic energy changes from $x$ to $\frac{x}{9}$ .

• A. $\frac{x}{9}$ eV
• B. $\frac{16x}{9}$ eV
• C. $9x$ eV
• D. $\frac{9}{16}$ eV

Answer 1

Answer: (B)

Change in kinetic energy
$x-\frac{x}{9}=\frac{8x}{9}$
From Bohr's model of the atom:
The kinetic energy in a state is equal to half of the potential energy in magnitude.
$\therefore Potentialenergy$ $\left(P.E\right)$ Change
$=2\times Kineticenergy\left(K.E\right)$ Change
$=2\times \frac{8x}{9}=\frac{16x}{9}$ eV