Across
- 2. a substance forms when an atom gains or loses an electron.
- 4. element with properties of metals and non-metals.
- 5. very reactive nonmetals.
- 7. row of the periodic table.
- 11. the central region of an atom
- 13. uncharged particle.
- 14. process of which elements produce energy and particles.
- 16. action around the nucleus.
- 17. a reactive metal-element.
- 19. the process of which atoms change.
- 20. elements that conduct electricity or heat and have a shiny appearance.
- 21. piece of an atom that determines the atomic number.
Down
- 1. extremely reactive element that must be stored in oil.
- 3. an element that does not react with other substances.
- 6. number of protons in the nucleus.
- 8. less reactive metals
- 9. atomic mass unit.
- 10. an atom with more protons than electrons.
- 12. elements with the opposite properties of metals.
- 15. result of an atom gaining an electron.
- 18. an atom that has the same number of protons and electrons, but a different number of neutrons.