Periodic Table
Across
- 2. group 18
- 6. group 1
- 7. Atoms of the same element that have different number of neutrons
- 9. group 3-12
- 10. group 17
- 12. where electrons are located
- 16. Elements 57-71
- 17. elements located on tops of the staircase
- 19. discovered nucleus
- 20. the number of protons in an atom
Down
- 1. positively charged particles
- 3. group 2
- 4. neutrally charged particles
- 5. elements on the left side of periodic table
- 8. negatively charged particles
- 11. center of an atom
- 13. elements on the right side of periodic table
- 14. elements 89-103
- 15. arranged elements by atomic number
- 17. Arranged elements by increasing atomic mass
- 18. total number of protons and neutrons