a group that satisfies the commutative law
(of a binary operation) independent of order; as in e.g. "a x b = b x a"
any number of entities (members) considered as a unit
arrange into a group or groups
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
form a group or group together
a set that is closed, associative, has an identity element and every element has an inverse