Across
- 2. subatomic particle with a positive electric charge
- 4. substance changes directly from solid to gas
- 5. has a definite volume but no definite shape
- 8. makes up 99.9% of mass of an atom
- 10. has elements with similar arrangement of electrons
- 11. substance changes from solid to liquid
- 13. the particles are negatively or positively charged ions
- 14. atoms with different numbers of neutrons
- 16. has elements with the same chemical property
- 19. organized elements into the periodic table
- 20. subatomic particle with no electric charge
Down
- 1. number of protons in an atom
- 3. number of electrons in an atom
- 6. formed when electrons in two or more atoms combine
- 7. substance changes from a liquid to a gas
- 8. least reactive family of metals & nonmetals
- 9. an element with no family
- 12. has no definite shape or volume
- 15. has a definite shape and volume
- 17. 75% of the elements are this
- 18. subatomic particle with a negative electric charge