Question

electrons moving from one energy level to another emit photons. always true sometimes true never true

Explanation:

When electrons move from a higher - energy level to a lower - energy level, they emit photons (according to the Bohr model of the atom). However, when electrons move from a lower - energy level to a higher - energy level, they absorb photons. So, electrons do not always emit photons when moving between energy levels.

Answer:

Sometimes True