Question

A plot of the kinetic energy $\left(1/2m{v}^2\right)$ of ejected electrons as a function of the frequency (v) of incident radiation for four alkali metals $(M_1,M_2,M_3,M_4)$ is shown below:
The alkali metals $M_1,M_2,M_3$ and $M_4$ are respectively

• A. Li, Na, K and Rb
• B. Rb, K, Na and Li
• C. Na, K, Li and Rb
• D. Rb, Li, Na and K

Answer 1

The correct option is B Rb, K, Na and Li

$\frac{1}{2}m{v}^2=hv-W$
High is the thershold frequency of metal greater will be the work function.
So,
$M_1\to Rb;M_2\to K;M_3\to Na;M_4\to Li$