Across
- 4. the table that organizes the elements by property and mass
- 5. the person who created the modern periodic table
- 6. the element with the symbol 'O'
- 7. a starting substance in a chemical reaction
- 9. the smallest particle of an element
- 11. the element with the symbol 'C'
Down
- 1. what atoms do during a chemical reaction
- 2. the element with the symbol 'H'
- 3. a fundamental substance that can't be broken down
- 4. a substance produced in a chemical reaction
- 8. a substance made of two or more different atoms combined
- 10. anything that has mass and takes up space