Across
- 1. the positively charged center of an atom.
- 5. elements aranged from ones with less protons to more.
- 8. the number of protons in an element.
- 9. a vertical column in the periodic table.
- 10. the particles that protons and neutrons are made of.
- 12. a particle with a negative charge.
- 13. atoms that have more neutrons than there base element.
- 14. the smallest piece of an element that still retains its properties.
- 15. the sum of electrons and protons in an element.
Down
- 2. the area around the center of an atom.
- 3. a particle with a positive charge.
- 4. a particle with a neutral charge.
- 6. a symbol of dots representing where protons are.
- 7. the weighted average mass of the mixture of its isotopes.
- 11. the horizontal rows of the periodic table.