If the binding energy of electrons in a metal is 250 kJ mol^(-1), what should be threshold frequency of the striking photons ?

If the binding energy of electrons in a metal is 250 kJ mol^(-1), what

1.	If the binding energy of electrons in a metal is 250 kJ mol^(-1), what should be threshold frequency of the striking photons ?
Answer» Solution :BINDING energy of 1 mole of ELECTRONS = 250 kJ `:.` Binding energ of 1 electron `= (250)/(6.022 XX 10^(23)) kJ = 4.15 xx 10^(-22) kJ = 4.15 xx 10^(-19) J` Threshold energy `(hv_(0))` = Binding energy `:. hv_(0) = 4.15 xx 10^(-19) J` or `v_(0) = (4.15 xx 10^(-19)J)/(h) = (4.15 xx 10^(-19) J)/(6.626 xx 10^(-34) Js) = 6.26 xx 10^(14) s^(-1)`