Final answer:
Homogeneous mixtures have uniform composition, while pure substances also have uniform composition and consist of only one type of matter. They are similar because both have consistent properties throughout the sample. The correct option is A.
Step-by-step explanation:
A homogeneous mixture differs from a pure substance in that a homogeneous mixture contains two or more substances blended uniformly throughout, whereas a pure substance consists of a single type of matter with a constant composition.
In a homogeneous mixture, components are not visually distinguishable and have the same composition from point to point. An example of this would be salt water. A pure substance can either be an element consisting of one type of atom or a compound made up of two or more types of atoms bonded together.
The correct answer to the given options is a) Homogeneous mixtures have uniform composition; pure substances have uniform composition. They are similar in that both can have the same composition throughout a sample.
Homogeneous mixtures and pure substances are uniformly mixed, even though pure substances cannot be separated into other kinds of matter by physical means, whereas homogeneous mixtures can be separated.