Question

Electromagnetic radiation of 5.16Ă—1016 Hz frequency is applied on a metal surface and caused electron emission. Determine the work function of the metal if the maximum kinetic energy (Ek) of the emitted electron is 4.04Ă—10-19 J.

Answer 1

Work function of the metal,
`W_o=3.38* 10^(-17)\ J`

Explanation:

We are given that

Frequency of the electromagnetic radiation,
`f=5.16* 10^(16)` Hz

The maximum kinetic energy of the emitted electron,
`K=4.04* 10^(-19)\ J`

We need to find the work function of the metal.

We know that the maximum kinetic energy of ejected electron

`K=h\\u-w_o`

Where h=Plank's constant=
`6.63* 10^(-34) J.s`

`\\u` =Frequency of light source

`w_o`=Work function

Substitute the values in the given formula

Then, the work function of the metal is given by :

`W_o=h\\u -K`

`W_o=6.63* 10^(-34)* 5.16* 10^(16)-4.04* 10^(-19)`

`W_o=3.38* 10^(-17)\ J`

So, the work function of the metal is
`3.38* 10^(-17)\ J`. Hence, this is the required solution.