If a culture in the lab starts with one human cell, how many cells will there be after 24 hours?

4 cells because the cells would divide.

and after water is usually warmed by the sun the water temperature raises and then evaporates .

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