The wave picture of light has failed to explain which of the following phenomena?

Light of intensity $10^{-5} \; W m^{-2}$ falls on a sodium photo-cell of surface area $2 \; cm^2$. Assuming that the top $5$ layers of sodium absorb the incident energy,estimate the time required for photoelectric emission in the wave-picture of radiation. The work function for the metal is given to be about $2 \; eV$. What is the implication of your answer?

Which of the following statements is true for photoelectrons emitted from a sodium metal surface?

On a photosensitive surface, if the intensity of incident radiation is increased, the stopping potential

What is the photoelectric effect?

$A$ photocell is illuminated by a small bright source placed $d \; m$ away. When the same source of light is placed $\frac{d}{2} \; m$ away,the number of electrons emitted by the photocathode would