2. Compounds Which of these is a compound? WHY? Compound – two or more elements BONDED together What do the colors represent?

3. Formulas How many ATOMS are in this compound? How many ELEMENTS are in this compound? Formulas – symbolize a compound NH 3 What color is Nitrogen? BLACK Hydrogen? BLUE

4. What does “BONDED” mean? Bonding means that the atoms are working together to become stable. How do atoms become more stable? –They FILL their outer orbitals!

5. How can Sodium & Chlorine become full/stable? Sodium: 1 valence e- Chlorine: 7 valence e- 11+ 17+

6. Is each atom now stable? YES! 11+ 17+ Sodium Chlorine

7. What happened to the charges? Sodium BEFORE11+ & 11-  NEUTRAL AFTER11+ & 10-  +1 Cl Na Chlorine BEFORE17+ & 17-  NEUTRAL AFTER17+ & 18-  -1 +

8. Now, the POSITIVE attracts the NEGATIVE! The atoms BOND! Cl 1 Na 1

9. The COMPOUND IS NOW NEUTRAL! Cl 1 Na 1

10. Draw Bohr models for Mg & O! Circle the electron(s) that will move. Draw an arrow to show WHERE they will move. Draw a picture of the final compound with the charge of each atom after the electron exchange!

11. OMg 22 12+ 8+

12. This is an Ionic Bond. Bond in which one atom takes an electron from another atom. Atoms become charged. VOCABULARY Ion – atoms with a charge Cation – positive charge Anion – negative charge OMg 22 Cation Anion Both are IONS!

13. Lewis Dot Structures Focus on the Valence Electrons Electrons are drawn in PAIRS!

14. Sometimes atoms SHARE electrons! Sometimes atoms can achieve full outer rings by SHARING electrons. Atoms are NOT charged! This is called a COVALENT bond. Hydrogen gas (H 2 ) http://www.visionlearning.com/libr ary/module_viewer.php?mid=55

15. Hydrogen + Hydrogen H H2H2 H

16. 2 Hydrogens + 1 Oxygen H2OH2O O HH

17. Ionic Bonds happen between… METALS AND NONMETALS!!

18. Covalent Bonds happen between… TWO NONMETALS!!

19. Identify as Ionic or Covalent compounds… SiO CO 2 KI BaF 2 Covalent Ionic

20. Which conducts Electricity? IONIC BONDS conduct electricity!! Why? Electricity is made of MOVING CHARGES!

21. Noble Gases DO NOT bond! Why? They already have full outer rings!

22. Alloys Elements that are mixed together but DO NOT bond are called alloys.

23. Alloys are mixtures. These are PHYSICAL changes. Bonding is a CHEMICAL change. Time for a MOVIE!!