Which type of scientific ststement is defined as "a possible explantion or answer to a scientific question that is based on prior knoledge or research and is tested"?

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

not sure if this what   you'r looking for would be percent composition

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex