A description Niels has a about why the wavelength of light absorbed by hydrogen has a certain value. Niels suggests the orbit of the electron in the hydrogen atom can only have certain radii, and when the electron "jumps" from one orbit to another, it emits light of an energy corresponding exactly to the difference in orbit energies. Christina decides to test the idea of her friend Anders that different metals make characteristic colors in flame. She mixes up a variety of metal solutions, then dips steel wires into each and puts each wire into a flame, noting the color of the flame in her record of this Anders dips a steel wire into a solution of copper sulfate and then puts it into a flame, recording his that the flame turns green. mi