Pure substance

Definition

A pure substance is a form of matter that has a constant composition and properties throughout. It can be either an element or a compound.

5 Must Know Facts For Your Next Test

1. Pure substances have uniform and definite compositions.
2. Elements and compounds are the two types of pure substances.
3. Pure substances cannot be separated into other kinds of matter by physical means.
4. The properties of a pure substance are consistent throughout the sample.
5. Examples include distilled water (a compound) and gold (an element).

Review Questions

Related terms

Element:

A pure substance consisting of only one type of atom, which cannot be broken down into simpler substances by chemical means.

Compound:

A pure substance composed of two or more elements chemically combined in fixed proportions.

Mixture:

A combination of two or more substances where each retains its own chemical identity and properties.