A material that is composed of only one type of particle

A material that is composed of only one type of particle is known as a pure substance. This can be either an element or a compound.

1. An element is a pure substance that is made from a single type of atom. Examples of elements include iron, copper, hydrogen and oxygen.

2. A compound is a pure substance composed of two or more different atoms chemically bonded to one another. Examples of compounds include water (H2O), carbon dioxide (CO2), and table salt (NaCl).

So, if a material is composed of only one type of particle, it is a pure substance, and it can be either an element if the particle is an atom, or a compound if the particle is a molecule.