Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

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Physics

Photoelectric Effect and Quantum Theory

Quick fact

Light can knock electrons out of metal, but only if it has enough energy—this was the key to discovering quantum theory.

Why this is interesting

Have you ever wondered why your phone screen lights up when you press a button? It’s not just electricity—it’s light behaving like particles.