A substance is a type of matter with uniform properties throughout. This means that a substance sample will have the same characteristics regardless of its size.
- One kind of substance is a chemical substance. A chemical substance is a specific type of matter with molecules with the same structure and composition.
- Chemical bonds hold these molecules together. Substances cannot be separated into their parts (elements or compounds) without breaking these chemical bonds.
- Substances can be generally classified into two main categories:
- Elements: The simplest form of a substance, elements are made up of only one type of atom.
- Compounds: These substances are formed when two or more elements chemically bond together.