Question

What evidence shows that light behaves as a wave & NOT a particle?

Use Dutch scientist Christian Huygen in your explanation

Answer 1

Light has the dual nature. It exhibits both properties of particle as well wave. Some phenomenons of the light are explained by particle nature like photo-electric effect, some phenomenons are explained using wave nature like interference and polarisation whereas some phenomenons are explained by both particle as well as wavw like reflection, refraction etc.
Christiaan Huygen was first to explain how wave theory can be attributed to explain the laws of geometric optics. Huygen's principle states that "Every point on a wave-front may be considered a source of secondary spherical wavelets which spread out in the forward direction at the speed of light. The new wave-front is the tangential surface to all of these secondary wavelets."

So he explained the rectilinear propogation of light using the the propogation of wavefront. This provides and evidence that light has wave nature.