Why does the color light emmitted by different substances when burned change?

Question

Why is the emitted light in a flame test for sodium (yellow), while the light emitted for strontium is bright red-orange?

Answer 1

Hi. Each element has a certain number of electrons located in many 'shells' or 'orbits' (take your pick. Both are wrong but help to explain this answer). When heated, the electrons tend to jump to a higher orbit, say, and when they jump back the photons they give off are of a particular frequency, which we perceive as color.

Answer 2

Its based on the quantum theory, how much energy an atom has determines the color of the flame. Like some gases burn a deep red, others burn a bright blue or white.

If you know the electromagnetic scale visible light goes from red to blue, blue having the most energy and smallest wavelength