Across
- 3. Electrons in the outermost shell of an atom
- 5. The most reactive group of metals on the periodic table
- 6. The part of the atom with a positive charge
- 7. An atom that has lost or gained one or more electrons
- 9. A substance composed of two or more chemical elements
- 11. The results of a chemical reaction
- 12. The least reactive group on the periodic table
Down
- 1. The heaviest part of an atom
- 2. Substance used to cause a chemical reaction
- 4. The smallest part of an atom
- 8. Where the protons and neutrons are found in a atom
- 10. the base unit of amount of a substance as determined by the International System of Units
- 13. The smallest unit of matter that forms a element