By subjecting it to extreme temperatures to test its purity

By exposing it to a contaminated environment to observe its reaction

By ensuring the substance consists of only one type of atom or molecule, with no impurities or other substances mixed in.

By mixing it with other substances to enhance its properties

helium

oxygen

nitrogen

carbon

A compound is a substance formed when two or more chemical elements are chemically bonded together.

A compound is a type of physical change

A compound is a substance formed by a single chemical element

A compound is a mixture of two or more elements

An element is a mixture of different types of atoms, whereas a compound is made up of only one type of atom.

An element is always a liquid, while a compound is always a gas.

An element and a compound are the same thing.

An element consists of only one type of atom, whereas a compound consists of two or more different types of atoms bonded together.