1. The Nature of Matter
Atoms and Bonding

2. Atoms
Atoms
The basic unit of matter.

3. Structure of an Atom Proton Electron Neutron Nucleus
Have the students label the subatomic particles, but do not describe. The students will use the diagram to make observations and define the particles.

4. Your Turn! Describe each of the subatomic particles in your own words.
Nucleus
Proton
Neutron
Electron
Prompts: Draw students to notice charges and locations of subatomic particles.

5. What do I need to know about those electron shells?
Electrons in the outermost level are called valence electrons.
Atoms are most stable when their outermost electron levels are filled.

6. Atoms and Bonding… IONIC BONDS
Ex: Sodium Chloride - Table Salt
Show the students the BEFORE and AFTER the chemical reaction diagrams, but do not explain yet what happened. Allow the students time to hypothesize/describe what they see happening.
BEFORE
AFTER

7. Your Turn!
Describe what happened in the BEFORE and AFTER steps of the chemical reaction.
Because Sodium would need 7 more electrons to fill its outer shell and Chlorine is only one short…the electron is transferred from Sodium to the Chlorine. Now the Sodium is positively charged (it has one less electron than proton) and the Chlorine is negatively charged (it has one more electron than proton). The oppositely charged elements are now attracted to each other and are bonded through an IONIC BOND.
BEFORE
AFTER

8. Atoms and Bonding… COVALENT BONDS
Ex: Water
BEFORE
AFTER

9. Your Turn!
Describe what happened in the BEFORE and AFTER steps of the chemical reaction. (HINT: Hydrogen only needs 2 valence electrons.)
Hydrogen only needs one more electron to fill its outer shell, while Oxygen requires two. The electrons are shared between the elements (they will fly around all the elements) creating a COVALENT BOND. This is a relatively stronger bond than an ionic bond since the elements are more closely bonded rather than just attracted by charge.
BEFORE
AFTER

10. WATER!

11. Your Turn! Solution Solvent Solute
Define each of the following terms (use the pictures as clues):
Solution
Solvent
Solute

12. Solution vs. Solvent vs. Solute
This is a visual hint to help students remember the difference between these three vocabulary words.
Solution

13. Solution vs. Solvent vs. Solute
Water is known as the universal solvent.
Let the students know that they will learn why water is such a good solvent!

14. Your Turn! Mixing with Water
Purpose: To determine which substances will mix with water, and to determine whether a solution is polar or nonpolar.
Remind the students to pay special attention to the background section of the lab. The students will learn the definitions for “ionic”, “polar”, and “nonpolar” from the background.

15. Properties of Water: Polarity
The oxygen atom in the water molecule (which has 8 protons) has a much stronger attraction for electrons than the hydrogen atom (which only has 1 proton).
Remember: Electrons carry a negative charge.
Make sure the students appropriately label the weight-lifter that represents oxygen vs. the one that represents the hydrogens. O H

16. Your Turn!
Describe what you notice about the diagram of the water molecule.
Students should note that the Oxygen end of the molecule is labeled as negative, and that the Hydrogen end of the water molecule is labeled as positive.

17. Properties of Water: Polarity
The oxygen atom “hogs” the electrons giving
one end of the molecule a negative charge
while the other end remains slightly positive. - O
More electrons leads
to a negative charge. H H + +
BECAUSE of this uneven pattern of charge…
water is called a polar molecule.

18. Your Turn! What is a polar molecule?
Students should now define “polarity”.

19. What’s so special about being a polar compound?
It makes water VERY good at dissolving many other substances.
It can dissolve other polar substances like sugars, as well as ionic compounds (compounds with a charge) like sodium chloride (salt).
Remind students that we already discussed that water is known as the “universal solvent”…and polarity is why!

20. Water dissolving salt…- Cl - Cl
Call to attention the orientation of the water molecules. Students should notice how the positive end of the water is attracted to the negative Chloride and the negative side is attracted to the positive Sodium.

21. Polar vs. Nonpolar
Notice that the nonpolar molecule does not have any charge associated with it!

22. Your Turn! What is a nonpolar molecule?
What did you learn in the lab about how polar and nonpolar substances interact?
Students should note that a nonpolar molecule lacks any charge. Nonpolar and polar substances do not mix.

23. Climbing Property of Water
Your Turn!
Climbing Property of Water
Purpose: To observe the movement of water through capillary action and to observe how this property of water can be used to separate a mixture of substances into the mixture’s individual components.
Purpose: To observe the effects of the attractive force between water molecules.
Remind the students to pay special attention to the background sections of both parts of the lab.
Walking on Water

24. Your Turn!
Watch the water animation to define and describe a hydrogen bond.
Ask the students to make a drawing to represent hydrogen bonds (they can use the closing image of the animation as a guide),

25. Hydrogen bonding creates… Cohesion Adhesion
The attractive forces between particles of the same kind (water to water).
The attractive force between unlike substances (water to penny).
Capillary Action is a result of cohesion of adhesion.
Capillary Action

26. Your Turn!
Why does a piece of celery sitting in blue water gradually turn blue?
Use the following vocabulary words in your answer:
Adhesion
Cohesion
Capillary Action

27. Surface Tension
The measure of how difficult it is to break the surface of a liquid.
Water has very high surface tension which can create a “skin” across the surface of water.

28. Additional Properties of Water: Heat Capacity
Water must gain or lose a large amount of energy for its temperature to change.
The energy needs to first break the hydrogen bonds before it can raise the temperature of the water.
Water has a high heat capacity!

29. Your Turn!
Why do you think it is important to us that water has a high heat capacity?
Let students explain their rationale and then introduce the term homeostasis.
Homeostasis: maintaining a stable internal environment

30. Additional Properties of Water: Three States of Matter
Water can naturally be found in all 3 major states of matter: solid (ice), liquid (water), and gas (water vapor)

31. Additional Properties of Water: Density
Ice is unique because it is less dense than liquid water.

32. Your Turn!
Why can it be beneficial to living things that the solid form of water is less dense than the liquid form?
Students should note that bodies of water that form ice could always remain frozen. Sinking ice could also crush aquatic organisms living below!

33. Acids
and
Bases

34. Water molecules can be broken down into ions.
H2O
(water) H+
(Hydrogen ion)
OH-
(Hydroxide ion) +

35. The pH Scale A measurement scale used to indicate the concentration
of H+ ions in a
solution.
(Ranges from 0 to 14.)
**Pure water has a pH of 7 (neutral).

36. Bases also known as Alkalines
Acids
Solutions with more H+ ions than OH- ions.
pH below 7
Bases also known as Alkalines
Solutions with more OH- ions than H+ ions.
pH above 7

37. Buffers
Weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH.