Atoms containing the same number of protons and different numbers of neutrons
isotopes
ions
neutrons
compounds

isotopes

Explanation:

The atoms of an element that have same number of protons but different number of neutrons are called as the isotopes of that element.

For example:  are the isotopes of Hydrogen

Ions are the charged species of an atom that are formed by the gain or loose of electrons.

For example:

Neutrons are the sub-atomic particles found inside the nucleus of an atom. They carry no charge.

Compounds are the substances that are formed when two or more atoms combine in a definite proportion.

For example: NaCl