Mention any one point of difference between pepsin and trypsin.

Pepsin is an enzyme which acts only in acidic medium ,trypsin is an enzyme which acts in alkaline medium

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.