Identify each of the highlighted materials as an element, a compound, or a mixture, and explain your reasoning.

Answer:

An element is a pure substance that consists of only one type of atom and cannot be broken down into simpler substances. A compound is a pure substance made up of two or more different elements that are chemically bonded in a fixed ratio; it can only be separated by chemical reactions. A mixture consists of two or more substances that are physically combined but not chemically bonded, meaning they can be separated by physical methods like filtration or evaporation.