Across
- 1. The columns are called
- 3. positively charged particle in an atom
- 4. theory of four elements
- 6. negatively charged particle in an atom
- 8. nucleus is a dense positively charged core
- 9. other term for group in periodic table
- 10. Bohr improved Rutherford’s model by adding the concept of orbits
Down
- 2. a systematic and organized way of presenting
- 5. neutral particle in an atom
- 7. rows are called: