Question

The binding energy of electron in a metal is 300 KJmol-1 ,the threshold frequency is

Answer 1

the threshold frequency is 7.4 X 10⁵ GHz

Explanation:

Given

E = 300 KJ/mol ⇒ 300000 J/mol

threshold frequency (ν) = ??

Solution

as we know that

E = hν

ν = E / h

where h = 6.6 X 10⁻³⁴ Js

ν = 300000 / 6.6 X 10⁻³⁴

ν = 0.45 X 10³⁹ Hz

for per atom

ν = 0.45 X 10³⁹ / 6.022 X 10²³

ν = 0.074 X 10¹⁶

ν = 7.4 X 10¹⁴ Hz

ν = 7.4 X 10⁵ GHz