Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 Å. Calculate threshold frequency `(v_(0))` and work function `(W_(0))` of the metal.

Explanation

Threshold frequency, `v_(0)=(c)/(lamda_(0))=(3xx10^(8)m*s^(-1))/(6800xx10^(-10)m)`
`=4.41xx10^(14)s^(-1)`
and work function of the metal `(w_(0))=hv_(0)`
`=(6.626xx10^(-34)J*s)xx(4.41xx10^(14)s^(-1))=2.92xx10^(-19)J`