Across
- 1. Vertical columns of the periodic table.
- 6. Scientist who arranged the periodic table by atomic number.
- 8. The particle with no charge found in the nucleus.
- 10. Number of protons in an atom.
- 12. The particle with a negative charge.
- 13. Elements that can act like metals or nonmetals depending on conditions.
- 15. The central region of an atom.
- 17. Elements in Group 1, highly reactive with water.
- 18. Elements found in the “stair-step” line, semiconductors.
- 19. The modern periodic table is arranged by increasing ______ number.
- 21. Scientist who first organized the table by atomic mass.
- 22. Shiny elements that are good conductors of heat and electricity.
- 24. Trend: Atomic size ______ as you go down a group.
Down
- 2. The particle with a positive charge.
- 3. Ability of an atom to attract electrons in a bond.
- 4. Most abundant element in the universe.
- 5. Group 18 elements, stable and unreactive.
- 7. Horizontal rows of the periodic table.
- 9. Elements that are dull, brittle, and poor conductors of electricity.
- 11. Smallest unit of matter.
- 14. Group 2 elements, reactive but less so than Group 1.
- 16. Atomic number 79, symbol Au.
- 20. Elements in Group 17, also called “salt formers.”
- 23. Energy needed to remove an electron.