Across
- 3. electrons in the outermost energy level
- 6. a particle that has mass and a positive electric charge
- 9. the change of one or more substances into another susbtance
- 12. shows all of the elements in an organized way
- 13. atoms of the same element that have different mass numbers
- 14. when an atom gains or loses electrons
- 15. a substance that is composed of atoms of 2+ elements that are chemically combined
- 17. Anything that has volume and mass
Down
- 1. a homogeneous mixture
- 2. a tiny particle with mass but no electrical charge
- 4. the attraction of two atoms for a shared pair of electrons
- 5. the number of protons in an atom's nucleus
- 7. a particle with little mass and a negative electric charge
- 8. bond the attractive force between two ions of opposite charge
- 10. a substance that cannot be broken down into simpler substances
- 11. Smallest particle of an element
- 16. the center of an atom
- 17. the sum of protons and neutrons in an atom's nucleus