Across
- 2. An atomic model that proposes electrons move in fixed energy levels
- 6. Weak forces of attraction between molecules
- 7. A substance that increases the rate of reaction by providing an alternative pathway
- 9. The minimum energy required to start a chemical reaction
Down
- 1. The total number of protons and neutrons in an atom
- 2. A substance that accepts a proton
- 3. The minimum energy required to remove one electron from a gaseous atom
- 4. The region around the nucleus where there is a high probability of finding an electron
- 5. A covalent bond formed when one atom donates both electrons
- 8. The electrostatic force of attraction between positive and negative ions