[Channel-talkchemistry] Reactions in chemistry workshop #2 post 2
Using macro demonstration to describe micro events can be very useful. ³
You can see a lot just by watching² is an excellent concept. Some of the
macro analogies that I thought where excellent where comparing an electron
microscope to one of the multiple pins toy. The one that you can leave an
impression of various objects. Other activities I use is a ³black box² to
show how indirect observation can lead to an understanding of something that
can not be observed directly like the atom or using a ³cheese candle² with a
slivered almond as the wick. By lighting the almond it looks like a candle.
I have the students tell me what they see vs. what they observe. I eat the
³candle at the end after I blow it out. Using water and isopropyl to
introduce solubility was very useful as presented by the video. Comparing
both to how each felt when placed on skin was a good comparison which lead
to similarities and differences. I also thought some of the role playing as
presented in the video did a good job having the students present their
ideas to each other.
Lastly I completed the Beers Law activity to show the relationship between
absorbance vs. concentration. The graphed data show a direct relationship
with the y intercept at zero as expected. I did run into a problem
calculating absorbance but solved it by determining the % transmitted (T) by
dividing the intensity at each concentration by the intensity of the blank.
I then calculated A= -log 10 ( T ).
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Received on Thu Oct 21 09:44:33 2004