In Thomson's experiment, he showed that an electrical current can be made to flow from a positive site to a negative site.
The formal charge of H = +1, because F in compounds can have only -1.
He used a magnet to find that the negatively charged particles to be smaller then the atom.
He discovered electrons.
CH2O. You can reduce 8, 16, and 8 to 1, 2, and 1. You just simplify the numbers. When there is no number after an element, it means that there is one of them.