chemical science, chemistry - the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions

closed chain, ring - (chemistry) a chain of atoms in a molecule that forms a closed loop

open chain - a chain of atoms in a molecule whose ends are not joined to form a ring

building block, unit - a single undivided natural thing occurring in the composition of something else; "units of nucleic acids"

molecule - (physics and chemistry) the simplest structural unit of an element or compound