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

Answer:

E = 0.965eV

Explanation:

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

$E=h \nu$        (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:

$1.54*10^{-19}J*\frac{6.242*10^{18}eV}{1J}=0.965eV$

The minimum energy needed is 0.965eV