1. Use the powerpoint with your “Study Guide” Try to answer each slide. THEN, Click on the next to get the answer and some notes!

2. A. Are these Ionic, Metallic, Covalent, or Network Covalent? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

3. A. Answers M Cu C_ NH 3 I MgCl 2 C CO 2 NC C - Diamond I MnO 2 C CH 4 I CaBr 2 Why? Only metal- metallic Only non-metal – covalent Metal and non-metal - ionic

4. B. Polar (P) or non-polar (NP)? Water Paint thinner

5. B. Answers Why? Asymmetrical = polar Symmetrical = non-polar P Water NP Paint thinner NP P

6. Physical Properties How things LOOK or ACT

7. C. Which is brittle and conduct only when liquid or dissolved in water? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

8. C. Answers MgCl 2 MnO 2 CaBr 2 Why? Ionic compounds are brittle (like salt) and conduct when dissolved in water Metals are shiny and bendable Network covalent (diamond) are very hard and not brittle Other covalents are usually gases or liquids at room temperature

9. D. Which is malleable (bend easily) and conduct electricity? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

10. D. Answers Cu Metals bend easily Metals always conduct because they have a “sea of electrons” around them (Each metal atom is trying to give up it’s electrons to the others so the electrons flow from one to the next.)

11. E. Which will dissolve in polar solvents like water? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

12. E. Answers NH 3 MgCl 2 MnO 2 CaBr 2 Why? “like dissolves like” (polar dissolves polar) Polar covalent AND ionic compounds dissolve in polar solvents like water (Ionic can be thought of as extremely polar)

13. Solubility The ability to dissolve. Dissolving always involves the mixing of two different substances. When a substance dissolves it breaks up and spreads out into the other substance.

14. F. Which will dissolve in non-polar solvents like paint thinner? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

15. F. Answers CO 2 CH 4 “like dissolves like” Non-polar dissolves non- polar Non-polar covalent dissolve in non-polar solvents like paint thinner. Metals and network covalent (diamond) do not dissolve in anything

16. Conductivity The ability to conduct electricity. Electricity is moving electrons – the valence electrons are transferred from one atom to the next, to the next, and so on.

17. G. Which will always conduct electricity (when solid or liquid)? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

18. G. Answers Cu Metals always conduct electricity because of the atoms are surrounded by a “sea of electrons” Each metal atom is trying to give away it’s valence electrons but no atom wants them. They pass them down the line!

19. H. Which will conduct electricity when liquid or dissolved? Cu NH 3 MgCl 2 CO 2 C - Diamond MnO 2 CH 4 CaBr 2

20. H. Answers Cu MgCl 2 MnO 2 CaBr 2 Why? Electricity is moving electrons Metals conduct (sea of electrons) Ionic compounds conduct when liquid (dissolved or melted) – the metal is trying to give away it’s electrons so they move Covalent never conduct (they share electrons and shared electrons don’t move)

21. Melting Point The temperature when something goes from a solid to a liquid. Substances with higher melting points can support more heat before turning to liquids. Turning from solid to liquid means the atoms have broken free from their position and can flow.

22. I. Number these “1, 2, 3, 4, or 5” 1 = highest melting point 5 = lowest melting point Cu NH 3 and H 2 O MgCl 2 and MnO 2 and CaBr 2 CO 2 and CH 4 C - Diamond

23. I. Answer – Highest (#1) C – Diamond Each atom is bonded to every other atom with covalent bonds. This makes it SUPER strong – strong means it will have a SUPER HIGH melting point.

24. Answer – next highest (#2) MgCl 2 and MnO 2 and CaBr 2 Ionic bonds are strong because they form crystals of opposite charges. Strong bonds means high melting point

25. Answer -3 rd highest (#3)? Cu Why? Metals are solid at room temp so they must be heated to melt.

26. Answer -4 th highest (#4) NH 3 and H 2 O Why? Polar molecules have a positive and negative end so they are “sticky” and hold on to each other to stay solid a little longer

27. Answer- Lowest (#5) CO 2 and CH 4 Why? Non-polar covalent molecules have no charge and so they cannot “hold hands” to stay together.