The wavelength you entered in the last problem is related to the energy required to eject an electron from sodium metal, the so-called work function. Use the relationship between photon wavelength and energy to calculate the work function of sodium (in electron-Volts) based on your measurement in the last problem.

2.30 eV

Explanation:

Some details of the problem are missing:

"Light of wavelength 540 nm is required to extract electrons from sodium. What is the work function of sodium?"

The equation that describes the photoelectric effect is

where:

is the energy of the incoming photon, with

is Planck constant

is the speed of light

is the work function of the material

K is the maximum kinetic energy of the emitted photoelectrons

The minimum energy needed by the photons to extract the photoelectrons is that for which the kinetic energy is zero, so

K = 0

Therefore we have

In this problem, we know that the wavelength of the incoming light is

Therefore, we can find the work function of sodium:

And converting into electronvolts,

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge