A student set up four test tubes containing starch solution in which to perform starch digestion. Starch is a carbohydrate. Supplies included amylase (an enzyme that digests carbohydrates) and an incubator. In which tube listed would starch digestion proceed most quickly?

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.