• Nov212009
    Phase Changes

    POSTED AT 09:54 AM

    Last week we worked on a Gizmo called "Phase Change". One activity challenged you to explore the effects of pressure on boiling point, melting point, and freezing point.  We agreed that the atmospheric pressure will affect the boiling point of water.
    Watch this 12 minute tutorial about Phase Change. Even though it may be geared for high school or college level, there will be many points made that apply to what we have done in class and it uses a graphs we saw when we used the PhET model.
    http://www.youtube.com/watch?v=Qp87Z4m8R-w&feature=SeriesPlayList&p=166048DD75B05C0D

    1. Does pressure affect melting points and freezing points? Defend your answer with help from the video tutorial. 

    This assignment is not due until Friday, December 4. Have a great Thanksgiving!
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    Nov132009
    Questions about States of Matter

    POSTED AT 02:33 PM

    Very impressive responses to last week's BLOG! I can see in your writing that you are really thinking about matter and how it behaves on a molecular level! BRAVO! Please watch this 2 minute video http://www.youtube.com/watch?v=zzVtbvVS2lQ to see how to boil water with ice. Towards the very end a quick and easy explanation will scroll down the page. You will see that many of you were right on! This was not a hoax! ;)
     
    This week please think of (and share) at least one question you have about our investigations with molecules and states of matter. Please share your thoughts about what parts you feel you understand and what part(s) are confusing. Thanks for all your great thoughts and questions!
     
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    Nov072009
    boil water with ice- for November 9th-13th

    POSTED AT 08:39 AM

     
    Recall how we were able to boil warm water by reducing the air pressure in the syringe. In areas where there is lower air pressure, like Mount Everest or Colorado for example, it takes less heat to boil water (water has a lower boiling point in areas above sea level). It is impossible to cook a hard boiled egg on Mt. Everest because the water will reach boiling but will not be hot enough to cook the egg!
     
    Using "molecular vision" explain what you think could be happening to the water molecules in the flask to cause the low air pressure. What would a PhET model look like for this phenomena? Refer back to your labs investigating pressure and temperature (with the PhET models and the syringe) to help you organize your thoughts.
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    Oct302009
    Witch's Brew

    POSTED AT 06:19 PM

    Witches Brew Demonstration:
    Phenolphthalein is a  indicator of acids and bases. It is colorless when mixed with an acid.  It turns pink when mixed with a base such as baking soda or ammonia.  Ammonia is a base, and it was in the 2nd and 4th beakers at the beginning of the demonstration. The first and third beakers had phenolphthalein in them. So when beaker 1 was poured into beaker 2 it turned pink. When beaker 3 was poured into beaker 4 it also turned pink (top half of the graphic).
     
    A. Remember when the pink beakers were poured into another liquid and it turned clear? What do you think was in that beaker to turn it from pink to clear? Use the information above to help you rationalize your answer.
     
    B. You know from 7th grade that BTB (bromthymol blue) is an indicator for CO2 and will turn green or yellow. Using the diagram above, tell me what pH you think CO2 might be. Is CO2 acidic or basic?
     
    C. Design a demonstration that would be similar to Mrs. Daigle's Witches Brew demonstration using BTB. What would you put in beakers 1 and 2? What liquid could you use to turn it back to blue?
     
     
     
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    Oct262009
    Properties of Gases Model

    POSTED AT 08:44 AM

     
    There is no official assignment this week. You can try to access the gas model we explored in class and tinker around with different variables. We will work with this model in a more official manner in the near future.
     
    User: student student
    password: ctms
    0 Comments Comments are closed

    Oct262009
    Properties of Gases Model

    POSTED AT 08:44 AM

     
    There is no official assignment this week. You can try to access the gas model we explored in class and tinker around with different variables. We will work with this model in a more official manner in the near future.
     
    User: student
    password: ctms
    0 Comments Comments are closed

    Oct162009
    Is it possible to see molecules and atoms?

    POSTED AT 06:14 PM

     
    Watch this short video that describes how scientists are able to "see" molecules.
    Respond to these questions:
    1. Is it possible to see atoms or molecules with an optical microscope like the ones we have in our classroom? (This question should sound very familiar.You answered this question for the Slide Show BLOG from a couple weeks ago.)
    2. a. In your own words describe how scientists know what molecules look like.
        b. Is this how a scanning electron microscope works?
    3.  a. Come up with an authentic question you have about atoms, molecules, or states of matter.
         b. Now tell me what you think the answer might be.
     
     
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    Oct112009
    Questions for Reflection About Density

    POSTED AT 10:18 AM

    In class we have been investigating density. We have compared and made estimates of the relative densities of solids and liquids. We have measured and calculated densities using the formula d=m/v. Very recently we began graphing the densities of certain liquids using mass and volume data. Finally, last week's blog had you looking at solids, liquids, and gases at a molecular level. Consider all that we have been doing to better understand density as you reply to the following questions:
     
    1. What do you think are the most important things you learned from these activities?
    2. What surprised you? Why?
    3. What questions are you left with?
     
     
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    Oct022009
    Solids, Liquids, and Gases at the Atomic Level

    POSTED AT 03:22 PM

     
    Use the above link to access the flash interactive. It has 59 slides to read and sometimes do something with. When you are finished, respond to these three questions. Don't forget to refer to your BLOG criteria.(Maybe it's taped to the top of your monitor?)
     
    1. Is it really possible to see molecules and atoms?
    2. In the depiction of a gas, the animation shows a lot of empty space between the molecules. What do you think is in this space?
    3. Why do you think the particles of a gas move so much more rapidly than the particles of a solid?
    17 Comments Add a comment

    Sep252009
    Egg in Solutions

    POSTED AT 03:40 PM

     
    Watch this one minute demonstration on YouTube called Egg in Solutions.
     
    What did the egg do in each beaker (A.B.C.D.)? What do you think each solution could be? Explain your reasonings using what you know about density. You may want to try it at home with water and other liquids before you decide.
     
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