Across
- 3. core of an atom
- 4. a group of electrons
- 7. has a negative charge
- 8. they don’t react
- 11. an atom that gives off radiation
- 13. nonmetal element that consists group 17
- 15. has same atomic number
- 16. has a positive charge
- 18. gains a positive charge
- 20. metallic elements
- 21. conduct heat and electricity
- 22. series of nonmetal elements
Down
- 1. has no charge
- 2. straight row in periodic table
- 5. sodium and potassium
- 6. a gas
- 9. has both metal and gas
- 10. a hard substance
- 11. em it’s radiation
- 12. a charged atom with no mass number
- 14. protons in the symbol on periodic table
- 17. barium and radium
- 19. molecules that float in the air
- 23. measure of atomic mass