Question

identify two facts the wave model of light failed to explain.
1.
2.

Explanation:

The wave model of light failed to explain the photoelectric effect (where light can eject electrons from a metal surface only if the light has a frequency above a certain threshold, regardless of intensity, which contradicts wave - like energy transfer expectations) and the discrete line spectra of atoms (where atoms emit light at specific wavelengths rather than a continuous range as would be expected from a wave - only model).

Answer:

1. The photoelectric effect.
2. The discrete line spectra of atoms.