Great question. Albert Einstein proved that light acts as both a particle and a wave in his 1905 paper. This is called wave-particle duality.
With quantum mechanics, it is easy to prove that light behaves as both a particle and a wave.
When UV light hits a metal surface, it causes an emission of electrons. This "photoelectric effect" proves how light behaves.
Full moon: All of the moon or sun appears covers by the shadow.
When the moon is waxing, it means that the lit part is getting larger (going towards a full moon)
When the moon is waning , it means that the lit part is getting smaller (going towards a new moon)
The new moon represents the start of a new lunar cycle and occurs approximately every 29 days.
Hope that help:)