Across
- 3. the number of protons in an elements nucleus
- 5. two or more atoms held together by covalent bonds constitute a:
- 7. smallest unit of matter
- 13. positively charged
- 14. decay spontaneously, giving off particles and energy
- 15. two atomic forms of an element
- 17. outermost shell of atom
- 19. attractions that hold atoms close together
- 20. number of electrons required to complete the atom
Down
- 1. number sum of protons plus neutrons in the nucleus
- 2. sharing of two pairs of electrons
- 4. used to measure neutron and proton mass
- 6. have no electrical charge
- 8. negatively charged
- 9. capacity to cause change
- 10. the energy that matter has because of its location or structure
- 11. the sharing of a pair of valence electrons by two atoms
- 12. sharing of one pair of electrons
- 16. atoms total mass
- 18. electrons that occupy the valence shell