1. Section V: Building With Matter
Lesson 25 You Light Up My Life
Lesson 26 Electron Glue
Lesson 27 Electrons on the Move

2. Lesson 25: You Light Up My Life
Classifying Substances
Key Question
How can substances be sorted into general categories?

3. ChemCatalyst
If you were to drop a spoonful of salt, NaCl, into a glass of water, what would happen?
If you were to drop a gold ring into a glass of water, what would happen?
What do you think is different about the atoms of these two substances? Why do you suppose the gold atoms don’t break apart?

4. You will be able to:
classify substances into four categories based on solubility and conductivity
explain the difference between the terms soluble and insoluble
begin to describe the atomic makeup of substances based on whether they are soluble and/or conduct electricity

5. Prepare for the Lab Work in pairs.
Wear safety goggles at all times during the lab.
Dissolve: To disperse evenly into another substance. For example, a solid can dissolve in a liquid.
Conductivity: A property that describes how well a substance transmits electricity.

6. Prepare for the Lab (cont.)
Dissolving and conductivity can be demonstrated with a powdered sports drink and a light bulb assembly like the one shown below.

7. Lesson 25 Discussion Notes
Sort the ten materials into these four groups:

8. Lesson 25 Discussion Notes
Generalizations about substances that do not light up the bulb:
Compounds made up of C, H, and O atoms do not conduct electricity.
Compounds made up entirely of nonmetals do not light up the bulb.
Compounds made up of a combination of metals and nonmetals do not light up the bulb when they are in their solid form.

9. Discussion Notes (cont.)
Generalizations about substances that do light up the bulb:
Everything that lights up the bulb has a metal atom in it.
Compounds made of metal and nonmetal atoms, such as salts, light up the bulb when they are dissolved in water.
(The sports drink is a solution of water, various salts, sugar, and a dye.)
Metal solids light up the bulb.

10. Discussion Notes (cont.)
Solubility and Conductivity

11. Discussion Notes (cont.)
We can place all the substances tested into one of the four categories.
Soluble: Describes a substance that is capable of being dissolved in another substance.
Insoluble: Describes a substance that is incapable of being dissolved in another substance.

12. Lesson 25 Wrap Up Lesson 25 Check-in
How can substances be sorted into general categories?
Not all substances dissolve in water.
Not all substances conduct electricity.
Solid metals and metal–nonmetal compounds dissolved in water conduct electricity.
Lesson 25 Check-in
Predict whether MgSO4(aq), commonly known as Epsom salts, will conduct electricity. State your reasoning.

13. Check-in
Predict whether MgSO4(aq), commonly known as Epsom salts, will conduct electricity. State your reasoning.

14. Lesson 26: Electron Glue Key Question Bonding
How are atoms connected to one another?

15. Lesson 26 ChemCatalyst
A gold ring is made up of individual gold atoms.
What keeps the atoms together? Why don’t they break apart from one another?
What parts of the atom do you think are responsible for keeping the atoms together in a solid?

16. Key Question
How are atoms connected to one another?

17. You will be able to:
define a chemical bond and describe the four basic types of chemical bonds
use chemical formulas to sort substances into bonding categories
predict the properties of a substance based on its chemical formula and bonding type

18. Prepare for the Activity
Work in pairs.
Chemical bond: An attraction between atoms that holds them together in space.

19. Prepare for the Activity (cont.)
Four Models of Bonding

20. Discussion Notes
The different locations of the electrons among atoms account for many different properties of substances.

21. Lesson 26 Discussion Notes (cont.)
Four Models of Bonding:
Mini-Activity: examine the 5 molecular models
1. What atoms do you think the colors stand for?
2. What is the name and chemical formula for each?
3. Decide what type of bonds are represented in each molecule, and add its chemical formula to Table 1.
3. Add thechemical formula for each compoundto the main chart

22. Discussion Notes (cont.)
Chemical bond: An attraction between atoms that holds them together in space
Ionic bonding: A type of chemical bonding that is the result of transfer of electrons from one atom to another.
Covalent bonding: A type of chemical bonding in which one or more pairs of valence electrons are shared between the atoms. Covalent bonding can be molecular covalent or network covalent.

23. Discussion Notes (cont.)
Metallic bond: A bond between metal atoms in which the valence electrons are free to move throughout the substance.
Molecule: A group of atoms covalently bonded together.

24. Discussion Notes (cont.)

25. Lesson 26 Discussion Notes (cont.)
The chart created in the previous lesson can now be labeled with the four types of bonds:
(Go back to Lesson 25 and add this labeling!)
Ionic Molecular Metallic Network covalent covalent

26. Lesson 26 Discussion Notes (cont.)
Bonding also relates to the type of atom in the substance—metal or nonmetal.
Metal atoms
Metallic
Nonmetal atoms
Network Molecular
covalent covalent
Metal and nonmetal atoms
Ionic

27. Lesson 26 Discussion Notes (cont.)
Four Models of Bonding:
What are these pictures trying to represent?
(What is the blue shading trying to show?)

28. Lesson 26 Discussion Notes (cont.)
Four Models of Bonding:
What are these pictures trying to represent?
(What is the blue shading trying to show?)
Valence electrons are distributed differently in each type of bond.

29. Lesson 26 Wrap Up How are atoms connected to one another?
A chemical bond is an attraction between atoms involving valence electrons.
There are four types of bonds: ionic, network covalent, molecular covalent, and metallic.
Valence electrons are distributed differently depending on the type of bond.
Imagine that you have a mystery substance that (i) does not dissolve in water but (ii) does conduct electricity.
What type of bonding will you probably find in your substance? Explain.
List one other other property of your mystery substance.

30. Lesson 26 Check-in
Imagine that you have a mystery substance that does not dissolve in water and does conduct electricity.
What type of bonding will you probably find in your substance? Explain.
List one other property of your mystery substance.

31. Lesson 27: Electrons on the Move
Electroplating Metals
Key Question
How can you extract an element from a compound?

32. ChemCatalyst
1. What is the charge on the copper ions in this copper chloride compound?
2. How do you think we could get solid copper from a sample of copper (II) sulfate, CuSO4?
Copper and chlorine atoms combine to form copper (II) chloride.

33. You will be able to: assemble an electroplating apparatus
explain how to extract elemental metal from an ionic compound through electroplating

34. Prepare for the Lab Work in pairs. Wear safety goggles at all times.
The solution contains acid, which is corrosive. Before handling the nickel strip, rinse it with water.
Note: We used nickel coins rather than nickel strips

35. Discussion Notes
It is possible to transform metal cations in solution into neutral metal atoms, using electricity.

36. Discussion Notes (cont.)
Aqueous copper (II) sulfate, CuSO4(aq), is really copper cations, Cu2+, and sulfate anions, SO42–.
Before connecting to the battery

37. Discussion Notes (cont.)
Once the battery is hooked up, one nickel strip has a positive charge, and the other has a negative charge.
After connecting to the battery

38. Discussion Notes (cont.)
Many elements are found in nature only in combination with other atoms in compounds.
While you cannot make gold by moving electrons, you can plate thin layers of gold onto jewelry.

39. Lesson 27 Wrap Up Lesson 27 Check-in
How can you extract an element from a compound?
Atoms are not destroyed when they combine to form compounds. Matter is conserved.
Ions are simply atoms or groups of atoms with charges on them because they either are missing electrons or have extra electrons.
Elements can be extracted from ionic compounds by moving electrons between atoms. (We did this with the battery & wires)
Lesson 27 Check-in
What is required to transform CuCl2(aq) into Cu(s)?
What is required to transform CuCl2(aq) into Au(s)?