premise: The theory goes that everything around us is built up of tiny particles called atoms. Some materials are made up of only one type of atom; these are called elements. An example is hydrogen. Others are made up of different sorts of atom bonded together into molecules. These are called compounds. Water, for example, is a compound made up of molecules that contain two hydrogen atoms and one oxygen atom. The force which holds atoms together is called bonds. Atoms are made up of even smaller particles such as neutrons, electrons and protons. Neutrons and protons are made up of even smaller particles. These have been called quarks and gluons. The search is on for the particles that make up quarks.
hypothesis: The atom is the smallest particle of matter.