Game: classify each clue by the experiment it points to first.

Choose the experiment that best matches each observation.

Brighter low-frequency light still does not eject electrons, but higher-frequency light does.

A heated cavity does not dump infinite energy into the ultraviolet even though a naive classical count says it should.

An excited gas emits only a few sharply defined colors instead of a smooth rainbow.

Individual detections arrive one by one, yet the long-run pattern shows alternating bright and dark bands.

Quantum mechanics