1. CHEMISTRY BELL RINGER IAN PG. 26 Week of 11/16/2015 Thursday 11/18/15 ANSWER PRACTICE PROBLEMS 1 & 2 ON PAGE 193 IN YOUR TEXTBOOK! BE PREPARED TO SHARE YOUR ANSWERS WITH THE CLASS

2. 7.2 Ionic Bonds & Compounds Bell Work: Predict the formulas of compounds formed from the following elements… a. Potassium & oxygen K2OK2O b. Magnesium & nitrogen Mg 3 N 2 c. Potassium & iodine KI a. Calcium & chlorine CaCl 2

3.  Most ionic compounds are crystalline solids at room temperature. They form repeating 3 dimensional patterns…

4.  The attractive forces in ionic bonds form very stable compounds; therefore, ionic compounds generally have high melting points.

5.  The coordination number is the number of ions of opposite charge that surround an ion in a crystal…  NaCl has a coordination number of 6

6.  Ionic compounds can conduct an electric current when melted or dissolved in water.

8. CHEMISTRY BELL RINGER IAN PG. 26 Week of 11/16/2015 Friday 11/19/15 PREDICT THE FORMULAS OF COMPOUNDS FORMED FROM THE FOLLOWING ELEMENTS… a.POTASSIUM & OXYGEN K2OK2O b.MAGNESIUM & NITROGEN MG 3 N 2 c.POTASSIUM & IODINE KI a.CALCIUM & CHLORINE CACL 2

9. THE TITANIC A Scary Story about an Alloy

10. The Titanic Set out from Southampton England to New York on April 10, 1912.

11. The ship weighed 52,310 tons. It took up the space of 4 city blocks and was 11 stories high.

12. A first class ticket cost $4700 (that would be equivalent to $50,000 in today’s money)!

13. Builders claimed the Titanic was unsinkable due to a double layer of steel along the bottom and 16 watertight compartments separated from each other in the hull. Even if the first 4 became flooded, the ship would stay afloat.

14. Confidence was so high, they only carried 20 lifeboats – enough for only half of the passengers.

15. On April 14, some warnings came in from other ships about icebergs in the area. All the warnings were dismissed by the ship’s captain.

16. 11:40 pm: Two crew members saw a large iceberg. The ship attempted to turn. The front side of the ship grazed the iceberg. 5 of the compartments were ruptured.

17. Damage occurred 20 feet down below the water surface. The increase in pressure at this depth caused the water to gush in at 7 tons per second.

18. The ship tipped forward as it flooded, causing more compartments to become flooded.

19. 3 hours after hitting the ice, the Titanic sank 12,600 feet down.

20. There were 2,228 people on board. Only 705 survived. The water temperature was 31 degrees F.

21. Now that we have been able to access the wreck, it has been determined that the ship’s steel had an unusually high sulfur content. Nonmetals, such as sulfur, are often added to steel to make it harder and more durable.

22. Iron, by itself is soft and malleable. But, adding too much nonmetal can make the product brittle. The steel of the Titanic was 10X more brittle than today’s steel.

23. Rivets that hold the steel together were also of poor quality. They contained high amounts of slag (a glassy residue that contains iron, oxygen and silicon) that also made them brittle.

24. What ifs….. What if the Captain had listened to other ships’ warnings? What if the Titanic had hit the iceberg head-on, rather than grazing it sideways? What if enough lifeboats had been stocked? What if the steel had been made differently? What if the rivets had been stronger?

25. 7.3 Bonding in Metals Metals are made of closely packed cations.  Valence electrons of metals are mobile and can drift freely from one part of the metal to another.  This explains why metals are: good conductors maleable ductile

26.  Metallic bonds are the attraction that holds the tightly packed cations and drifting electrons together.

27.  Metals are also crystalline – the atoms are arranged in compact and orderly patterns… Body centered cubic **every atom has 8 neighbors

28. Face centered cubic… Every atom has 12 neighbors

29. Hexagonal close packed Every atom has 12 neighbors (more tightly packed than face-centered cubic)

30. Alloys  Most metals you encounter are alloys.  Alloys are mixtures composed of 2 or more elements, at least one of which is a metal.  Brass = copper + Zinc  Sterling silver = silver + copper  Bronze = copper + tin  Properties of alloys are often superior to those of the individual elements that make the alloy.

31. Steel  The most useful and important alloys today are steels.  Steel = Fe + C and some combination of the following:  B  Cr  Mn  Mb  Ni  W  V

33.  Substitutional alloy – if atoms in an alloy are about the same size, they can replace each other in the crystal.  Interstitial alloy – if the atoms in the alloy are different sizes, the smaller atoms can fit into the spaces between the larger atoms.