Classification of Matter

Compounds and Their Composition:

• A compound is a substance made up of two or more different types of atoms bonded together.

• The atoms in a compound combine in whole-number ratios. For example, a compound could have 1 red atom for every 1 blue atom.

• This means that each particle of the compound always has the same number of atoms in the same ratio, giving the compound a fixed composition.

• Because of this fixed ratio, compounds are considered pure substances. Every particle is the same, and there’s no mix of different types of substances.

A mixture:

contains 2 or more substances.

Mixtures:

• A mixture is made by combining two or more substances without changing their chemical identities.

• Mixtures can be homogeneous or heterogeneous:

  • Homogeneous mixtures have the same distribution of components throughout (like a well-mixed smoothie).

  • Heterogeneous mixtures have uneven distribution of components (like a salad, where you can see the individual ingredients).

Classification of matter