Which of these statements about mixtures is true?

Mixtures are made up of elements bonded together.

Elements and compounds are types of mixtures.

Pure substances are made up of mixtures combined in specific ratios.

Mixtures are classified based on the distribution of particles in them.

The best answer from the choices would be the last option. Mixtures are classified based on the distribution of particles in them. The classification are called homogeneous and heterogeneous mixtures. The former type describes a mixture where all components are distributed evenly. The latter type is a mixture where the components do not have uniformity in the mixture.