Physics
Excited State
Quick fact
When an electron in an atom drops from an excited state to the ground state, it can emit a photon of light with a precise color—this is why different elements produce different flame colors in fireworks.
Why this is interesting
You've seen a neon sign glow or a glow-in-the-dark toy shine—but have you ever wondered why they emit light long after being charged? The answer lies in a temporary, high-energy state of matter called an excited state.