Which of the following phenomena support the idea that light is a wave? A. Light diffracts when it passes through openings and around obstacles.
B. All of these
C. Light bends when it passes into a new medium
D. Light exhibits interference patterns.

Wave theory of light explains the phenomena of interference, diffraction, scattering, dispersion, polarisation etc. Complete solution: Around 1700, it was concluded by Newton that light was a group of particles. It was called corpuscular theory.

The light particle conceived by Einstein is called a photon. The main point of his light quantum theory is the idea that light's energy is related to its oscillation frequency (known as frequency in the case of radio waves). Oscillation frequency is equal to the speed of light divided by its wavelength.

a coal burning power plant

when it gains or loses electrons