What is the smallest division that a substance can be broken down to without separating its individual atoms?

The smallest division that a substance can be broken down to without separating its individual atoms is a molecule. A molecule consists of two or more atoms that are chemically bonded together. When a substance is in the form of a molecule, it retains its chemical properties and can exist independently as a single unit.

While an atom is the basic unit of matter, breaking it down further would separate it from its chemical identity and individual properties. Compounds are made of two or more different elements that are bonded together, and an element is a pure substance that cannot be broken down into simpler substances by chemical means. Thus, if you were to break a compound down to its individual elements, you would lose the unique characteristics of the compound itself.

Therefore, a molecule is the correct choice as it represents the smallest unit of a chemical substance that retains its chemical properties while still being composed of individual atoms securely bonded together.