Across
- 2. is formed when an atom gains or loses an electron
- 4. negatively charged particles found in energy levels around the nucleus
- 7. represented by a specific chemical symbol
Down
- 1. is a group of atoms bonded together
- 3. positively charged particles found in the nucleus
- 5. is a pure substance composed of differentelements chemically joined
- 6. neutrally charged particles found in the nucleus