Final answer:
Substances can be classified as pure substances, heterogeneous mixtures, or homogeneous mixtures based on their physical properties and composition. A pure substance is made up of only one type of particle, such as an element or compound. Heterogeneous mixtures consist of visibly different substances, while homogeneous mixtures are uniformly distributed throughout.
Step-by-step explanation:
The classification of substances as pure substances, heterogeneous mixtures, or homogeneous mixtures is based on their physical properties and composition.
A pure substance is made up of only one type of particle and cannot be separated into simpler substances by physical means. Examples of pure substances include elements and compounds. An element is a substance made up of only one type of atom, such as gold or carbon. A compound is a substance made up of two or more different types of atoms chemically bonded together, such as water (H2O) or carbon dioxide (CO2).
A heterogeneous mixture is a mixture that consists of visibly different substances or phases. It is not uniform throughout and can be separated physically. Examples of heterogeneous mixtures include a cheese sandwich and a wooden spoon.
A homogeneous mixture, also known as a solution, is a mixture that has a uniform composition throughout. It consists of two or more substances that are evenly distributed at the molecular or atomic level. Examples of homogeneous mixtures include lip balm and a silver necklace.