Light with a wavelength of 400 nm strikes the surface of cesium in a photocell, and the maximum kinetic energy of the electrons ejected is 1.54 x 10‐19j. calculate the longest wavelength of light that is capable of ejecting electrons from that metal. (1 nm = 10‐9 m)

The longest wavelength of light that is capable of ejecting electrons from that metal is 1292 nm.

Explanation:

Given that,

Wavelength = 400 nm

Energy

We need to calculate the longest wavelength of light that is capable of ejecting electrons from that metal

Using formula of energy

Put the value into the formula

Hence, The longest wavelength of light that is capable of ejecting electrons from that metal is 1292 nm.