Why do different chemicals emit different colors of light when heated or excited?

• A. Because chemicals emit light by reflecting ambient light rather than producing their own.
• B. Because each chemical has a unique set of energy levels for its electrons, resulting in distinct wavelengths of emitted light.
• C. Because the color of emitted light depends only on the temperature at which the chemical is heated.
• D. Because all chemicals absorb the same wavelengths but emit different ones due to their mass.

Answer: (B)

Verified step by step guidance

1. Understand that when chemicals are heated or excited, their electrons gain energy and move to higher energy levels (excited states).
2. Recognize that when these excited electrons return to lower energy levels (ground states), they release energy in the form of light (photons).
3. Know that the energy difference between these levels is unique for each chemical because each element or compound has a distinct electronic structure.
4. Recall that the energy of the emitted photon determines the wavelength (and thus the color) of the light, using the relationship \(E = \frac{hc}{\lambda}\), where \(E\) is energy, \(h\) is Planck's constant, \(c\) is the speed of light, and \(\lambda\) is wavelength.
5. Conclude that because each chemical has a unique set of energy levels, the emitted light has characteristic wavelengths, resulting in different colors for different chemicals.