What is “Roy G. Biv,” and what does it stand for?

This flow chart shows the amount of energy that is emitted by each type of light. ultraviolet > blue light > yellow light > red light (maximum energy) (minimum energy) in an experiment, shining which type of light on a strip of metal would be least likely to produce the photoelectric effect? ultraviolet light dim blue light bright red light bright yellow light

Chemistry worksheet - i am not sure what they are asking for exactly?

The same side of the moon always faces earth because the