Kicking off Unit 6

This has been the semester from h*ll.  Have I already said that?  Yeah, I think I have.

Last week was spring break, which was absolutely lovely.  Prior to spring break, we flew through Unit 5 in about 4 days.  The students learned about the mole, they learned how to do conversions with Avogadro's number, and they learned how to do molar mass conversions.  No real labs, and I barely used the modeling curriculum-- just previous year's PowerPoints and grill & drill practice worksheets.  We ran out of time before spring break to do percent composition and empirical formulas.  I will pick them up at some other point in time... IF there is time.  The EOC is in 4 weeks and we have so much to do.

Today we began Unit 6 with a "charge" lab.  I chose not to do the Sticky Tape Lab.  In my modeling workshop, I remembered that lab being extremely time consuming.  We DO NOT have time. Instead, I adapted a lab I have used in the past called "Electrons on the Move," which can be completed in less than 30 minutes.  Obviously I did not call it that this time around-- we referred to it as "The Charges of Matter" lab.

Basically, it's a static electricity lab composed of six stations.  Students rub balloons and plastic objects on fabric and see the attractions and repulsions.

Before the lab, we discussed Democritus and Dalton's atomic theories, then I told them there was another scientist named JJ Thomson who added to the atomic theory based off his work with electrical charges.  We discussed the idea of charges.  Where have we seen positive/negative charges or ends of something in the lab so far (batteries, magnets)?  We discussed how like charges repel, opposite charges attract.  They were told the purpose of the lab was to determine if the objects in the lab had charges.  They were to draw a before and after sketch of each station, then assign charges to the objects.

Each lab group was assigned a single station to whiteboarded a verbal explanation and a diagram, both of the charges and of the particles.

Some examples (missing station 6):

Um... sort of not really

A little better

Not too bad

At least they were thinking about it

As a class, we came to the conclusion that:
1. Matter can have positive, negative, or neutral charges.
2. The charge of matter can change.
3. In the lab, the charge changed without changing the particles.

We didn't go into details on "positive" and "negative" yet.  Most have at ton of misconceptions in that department, but hopefully we'll clear them up tomorrow when we introduce the idea of electrons.

I sent them home with the online notes activity about JJ Thomson's experiments included in the curriculum.  It links students to A Look Inside The Atom to learn about JJ Thomson's cathode ray experiments.  I hope to heck that at least some of them attempt it so we can move on quickly.