Chemistry Regents Practice Test 2025 – Complete Prep Resource

The statement that an element is a pure substance made of one type of atom, while a compound is made of different atoms, accurately defines the fundamental distinction between elements and compounds. An element is considered the simplest form of matter that cannot be broken down into simpler substances by chemical means. Each element is composed entirely of one type of atom, which is characterized by its unique number of protons.

In contrast, a compound is a chemical combination of two or more different types of atoms bonded together in fixed ratios. Compounds have distinct properties that are different from the properties of the individual elements that compose them. This characteristic of compounds arises because the atoms interact through chemical bonds (ionic or covalent), resulting in new substances with unique properties.

Understanding this difference is crucial for grasping the basic principles of chemistry, as it lays the groundwork for more complex concepts such as chemical reactions, molecular structure, and the nature of chemical substances.