1			2
					3												4
				5							6
																			7
				8			9							10							11
		12
13										14			15
						16
17
						18				19
20		21
						22		23
24				25									26
27
		28					29
		30

Across 5. Elements in the same vertical group are special because they don't ....... in the same way. 6. What does the outer number of electrons on a shell determine, their ....... ? 9. What is on the shells of atoms ? 13. Element consist of ....... atom. 15. What group is lithium in ? 16. The atomic number tell us about how many ....... are in the atomic nucleus ? 17. How many electrons can fit on the second shell ? 19. What is the atomic mass for silicon ? 21. What is the atomic mass of oxygen ? 22. Ionic compounds have high melting points because it takes a lot of energy to break the ....... apart. 24. What group is boron in ? 26. The nucleus is the ....... of the atom. 27. What is in the center of an atom ? 30. What is the element for the symbol O ?

Down 1. Ionic bonding is where ....... elements bond. 2. How many groups are their in the periodic table ? 3. What is the symbol for neon ? 4. What is an element ? 7. In a chemical reaction it's a chemical change, splitting or ...... atoms. 8. How many electrons can fit on the third shell ? 10. Covalent bonding is where ....... elements bond. 11. Ionic bonding is where ....... elements bond. 12. What does the atomic mas tell us the about the atom, how much it ....... ? 14. What is the element for the symbol K ? 18. Almost the whole mass of the atom is concentrated in the ....... 20. The nucleus contains ....... ans neutrons 23. How many electrons can fit on the first shell ? 25. The amount of ....... varies in electron ? 28. Ionic bonding is bonding between two ........ by transfer of electrons. 29. What is the symbol for zinc ?