1. are atoms of an element with different numbers of neutrons 2. positively charged particles of the central nucleus of an atom 3. electrically neutral particles of the central nucleus of an atom are negatively charged particles surrounding the central nucleus of an atom 5. are two or more atoms held together by a chemical bond

The answer to your question is below:

Explanation:

1. _Isotopes__ are atoms of an element with different numbers of neutrons

2. _Protons positively charged particles of the central nucleus of an atom

3. _Neutrons__ electrically neutral particles of the central nucleus of an atom 4.__Electrons__ are negatively charged particles surrounding the central nucleus of an atom

5. _Molecules___ are two or more atoms held together by a chemical bond