A substance formed when two
or more chemical elements are
chemically bonded together?

Can someone me with questions 12 and 13 plz.

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

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?