both 6th and 7th graders have tests tomorrow.  Study your Study Guides, and take a look at your notes.  If you can't understand something, we'll have a brief Q & A before the test starts.  Don't forget to bring your study guides to the test to get credit for your studying! 

E.C. for my blog readers:  How many grams in 1 kg?  Write it on your Water Cycle Diagram (labeled with stages: ecpc), and turn in tomorrow at the beginning of the class.

Here are the Study Guide answers for my 6th graders:
1. What is a solution?   A solute dissolved in a solvent.

2. How is a solution different from other kinds of mixtures?   A solution is a mixture that is Evenly mixed. You’ll know its evenly mixed because it will be clear (“transparent”), not necessarily colorless.

3. How is a solute different from a solvent?   A solute is the dissolved material.  A solvent is the material that does the dissolving.

4. Imagine that you mix a bag of pebbles, salt, and wood chips. If you pour these materials into a bucket of water, the pebbles sink, the salt disappears, and the chips float. What is the solvent, solute, and precipitate?

Solvent = water
Solute = salt
Precipitate = pebbles

5. What compound is called the “Universal Solvent”? Why?   Water, because it is so good at dissolving so many materials.

6. What are the two broad classes of contaminants? Give an example of each.
Chemical – man-made
Biological – from living things or once-living things.

7. What are the stages of the Water Cycle?
Evaporation
Condensation
Precipitation
Collection, including:
     Surface water runoff
     Groundwater
     Gathering in ocean
     Transpiration from plants, use by animals

8. In which stages of the water cycle can water become contaminated?
Collection, including:
    Surface water runoff
    Groundwater
    Gathering in ocean
    Transpiration from plants, use by animals

9. Difference between diluted solution and a concentrated solution: diluted has lots of solvent, not much solute, while concentrated has little solvent and lots of solute. Ex: a glass of water with a half-teaspoon of Kool-Aid mix is a diluted solution, but a glass of water with a cup (72 teaspoons) of drink mix will be very concentrated.

10.  10 ppm or 100 ppm?  Most concentrated is 100 ppm.

11. Serial dilution:  A series of steps in which you water down a solution by a set multiple each time, resulting in a very diluted solution.  ex: Dissolve 1 drop of food coloring into 10 drops of water (10% or 100,000 ppm); then take 1 drop of THAT solution into 10 drops of water (1% or 10,000 ppm),  then dissolve 1 drop of THAT solution into 10 drops of water (.1% or 1,000 ppm).

12. If you have an 80 ppm HCl solution in cup 1, then dilute it by 1/2, you'll have a 40 ppm solution in cup 2, a 20 ppm solution in cup 3, and a 10 ppm solution in cup 4.

13. Methods we used or read about to remove pollutants from solution: evaporation / distilling / flocculation / coagulation / filtering.

14. "Neutralize" means to remove the acidic or basic nature / properties of a solution by adding base to an acid, or by adding acid to a base to achieve a neutral pH of 7 (water).  Neutralization reaction produces water and a salt.

15. Baking soda added to vinegar will neutralize the acid, therefore it must be a base.

16. Properties of acids: taste sour, corrode metal and tissue, pH <7, react with indicators, conduct electricity.

17.  Properties of bases: taste bitter, feel slippery, corrode tissue, pH >7, react with indicators, conduct electricity.

18. a. Wendy's experiment was poorly designed; it has more than one independent variable, and that is too many. b. Independent variables include light, water, type and amount of fertilizer. Dependent variable is plant height. Control group is the first row, where the plants got no fertilizer. Controlled (constant) variables: none stated. "Variables" includes all variables in the above groups.  c. The experiment could be reproduced, because the amounts of variables was recorded.   d. Total amount of fertilizer was not controlled: row A plants got 0 g fertilizer, which would work well as a control group; row B got 19 g, Row C got 11 g, and row D got 19g.

19. Draw and label on SPP the water cycle and its stages, showing how water changes state in each stage of the water cycle, and draw the pH scale, showing which numbers are acidic, basic, and neutral.