Question

the binding energy of electron in a metal is 300 kj mol ^-1 the threshold frequency is​

Answer 1

Explanation:

E = hν therefore

ν = E/h

The rest is simply calculation as follows:

ν ~ (176000 [J/mole] / 6.022*10^23 [/mole]) / 6.626 * 10^-34 {J.s] ~ 4.41 * 10^14 /s

ν ~ 4.41 * 10^5 GHz

Note that you need to convert the energy into Joules (rather than kilojoules) and the answer needs to be per atom of the metal rather than per mole.