Chapter 27, Problem 5Q

To determine

What can you say about the work functions of the two metals?

Answer to Problem 5Q

Solution:

The work function of the second metal is smaller than the first metal.

Explanation of Solution

If the threshold wavelength increases, then the frequency would decrease (as wavelength and frequency are proportional to each other).

Work function of a material is given by ${\varphi }_0=\frac{h}{{\lambda }_0}$

Here ${\lambda }_0$ is threshold wavelength and h is plank constant.

If the wavelength of the second metal is greater, then the second metal would have the greater work function as the electrons emitted from the second metal leave with less energy.