Which one of these is non-divisible?

Monochromatic light of frequency $6 \times 10^{14} \,Hz$ is produced by a laser. The power emitted is $2 \times 10^{-3} \,W$. How many photons per second on an average are emitted by the source? (Given $h = 6.63 \times 10^{-34} \,Js$)

The value of Planck's constant is

When light of wavelength $\lambda$ is incident on a photosensitive surface,photons of power $P$ are emitted. The number of photons $n$ emitted in time $t$ is: [$h$ = Planck's constant,$c$ = velocity of light in vacuum]

Consider the figure for photoemission. How would you reconcile this with the law of conservation of momentum? Note that light (photons) has momentum in a different direction than the emitted electrons.

$A$ particle which has zero rest mass and non-zero energy and momentum must travel with a speed