Atoms, Ions, Molecules (Biology)

Ion

atom that has gained or lost one or more electrons

Ionic Bond

chemical bond formed through electrical force between oppositely charged ions

Covalent Bond

chemical bond formed when two atoms share one or more pairs of electrons

Atom

smallest basic unit of matter

Compound

substance made of atoms of different elements that are bonded together in a particular ratio

Element

substance made of only one type of atom that cannot be broken down by chemical means

Molecule

two or more atoms held together by covalent bonds; not necessarily a compound