How is the light emitted by an excited element different from white light

An element emits light when an electron is raised to a higher orbital and falls back. The energy level of each electron can only change by a fixed amount, so the light emitted can only be a single frequency/color. If several electrons are excited then several colors are emitted. The combination of colors uniquely identifies the atom that produced them.

White light is by definition whatever the sun puts out.

Well. One you see when you die (white light). It's A TRiCK, dont take that path, it leads to the sun and you're going to burn up in a flame. The devil can sure be a tricky beyotch.

And if you dont know what an excited element is... Then you must still be a virgin. Give it time, padawan, you will learn. Oh you will learn...