Understanding Pure Substances and Mixtures

What is a characteristic of a pure substance?

• It can be easily separated into its components.

• It has a constant composition and distinct chemical properties.

• It consists of two or more substances mixed together.

• It is always a mixture of elements and compounds.

Which of the following is an example of a homogeneous mixture?

• Water and oil

• Kool-Aid

• Iron filings and sand

• Salad

What is the main difference between homogeneous and heterogeneous mixtures?

• Homogeneous mixtures have a uniform composition throughout, while heterogeneous mixtures do not.

• Homogeneous mixtures consist of substances that are not dissolved, while heterogeneous mixtures do.

• Heterogeneous mixtures have a uniform composition, while homogeneous mixtures do not.

• Homogeneous mixtures can be easily separated, while heterogeneous mixtures cannot.

In the lab demonstration, what method was used to separate iron filings from the mixture?

• Dissolving in water

• Filtration

• Evaporation

• Using a magnet

After separating the sand from the saltwater, what type of mixture is the saltwater considered?

• Compound

• Homogeneous mixture

• Heterogeneous mixture

• Pure substance