Across
- 6. noble gases are also called as ----- gases
- 7. elements from group 3 to 12 are-------- metals
- 8. atomic number is six
- 9. modern periodic law
Down
- 1. valence electons of noble gases
- 2. the revolving path traced by electrons
- 3. Are also called energy levels
- 4. element which have no neutron
- 5. proposed atomic theory