Final answer:
A substance made up of carbon and hydrogen atoms bonded together describes a compound, which is characterized by having a fixed ratio of two or more different elements chemically combined.
Step-by-step explanation:
An example that describes a compound is a substance made up of carbon and hydrogen atoms bonded together. A compound is a substance with a fixed ratio of two or more different elements chemically combined. Elements like carbon (C) and hydrogen (H) can bond in specific ratios to form a variety of compounds, such as methane (CH4), where four hydrogen atoms bond with one carbon atom.
This is different from a mixture where the elements are not chemically bonded, such as a substance made up of iron and nickel atoms that are not bonded together.