Question

The minimum frequency of light needed to eject electrons from a metal is called the threshold frequency, ????0 . Find the minimum energy needed to eject electrons from a metal with a threshold frequency of 2.47×1014 s−1. g

Answer 1

E = 0.965eV

Step-by-step explanation:

In order to calculate the minimum energy needed to eject the electrons you use the following formula:

`E=h \\u` (1)

h: Planck' constant = 6.626*10^{-34}J.s

v: threshold frequency = 2.47*10^14 s^-1

You replace the values of v and h in the equation (1):

`E=(6.262*10^(-34)J.s)(2.47*10^(14)s^(-1))=1.54*10^(-19)J`

In electron volts you obtain:

`1.54*10^(-19)J*(6.242*10^(18)eV)/(1J)=0.965eV`

The minimum energy needed is 0.965eV