Across
- 2. A simple substance that cannot be broken down into smaller pieces
- 3. The basic unit of a chemical element
- 6. A thing that is composed of two or more separate elements ( a mixture)
- 7. A constant related to the properties of a product
- 8. A positive charge region at the center of the atom
- 9. A large body of matter with no definite shape
Down
- 1. A subatomic particle with a negative charge
- 4. A subatomic particle occuring in a atomic nuclei
- 5. A group of atoms bonded together
- 7. A system of electron surrounding the nucleus