which consequently contain a definite number of protons. (The atoms may be bound together to form molecules, as in the case of the diatomic oxygen molecule 
) [P7.1, P8.1]
traditionally is: a substance which cannot be divided or separated by chemical means, including heating and passing of electrical current. [P8.1]
currently, is more appropriately defined: as matter consisting of atoms characterized by a single atomic number which consequently contain a definite number of protons. (The atoms may be bound together to form molecules, as in the case of the diatomic oxygen molecule ) [P7.1, P8.1]
Copyright 1997, The Open University