If you look at a picture of the earth from space, it looks like there is an awful lot of water on the earth. Is that true?

eukarya because is is like alche and b is bacteria and d is animals

explanation:

a physical change is being made.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds