It was the empty terrible feeling in the pit of my stomach at 9:30 at night that really bothered me as I am wading through the stack of papers that I was grading. I had the students do experiments, worksheets, I lectured and there was homework. Some of the students could “do” what I thought was science. They could calculate the answer. They could balance the equation.
Like most chemistry teachers, one of the first things I go over in the beginning of the year is unit conversions. Students come into my class with all sorts of prior knowledge concerning unit conversions; some good, some bad and some downright ugly.
I always feel a need to start the year off with an activity that ties in observations and conclusions but I also know that most students have had that in science classes since the early grades. Is there a way to revisit an old topic with a new or more challenging bent?
I had a tough week. I had a front row seat in which I witnessed someone almost lose their life. I also almost accidently deleted both of my class websites just days before the kids walk in as we are starting a one to one lap top program. Here is the amazing part to all this...I get something that we all get as teachers every year...a second chance.
A quick search on Amazon for a package of 144 ping pong balls and a trip to the arts and crafts store for paint, magnets, and glue and I was ready to start making my own class set of model kits.
I am a very firm believer that the world of physical science can be visualized and is an excellent medium for teaching students to model and to picture what happens at the molecular level. The first topic we decided to explore was balancing chemical equations. This seems like such a simple topic to chemistry teachers but I have found that it can be quite challenging for many of my inner city students. The first thing they ask me for is a list of rules that they can follow. We can discuss the problems of algorithmic teaching in a later post! For the time being let’s talk about how to get students to understand why they need to balance equations and discuss what we can call “Conservation of Atoms”.
In Chemical Mystery #7, a can of Coca-Cola was observed to sink in one container of water and yet float in another! This trick made use of the fact that the density of water changes with temperature.
Q: Does an unopened can of soda pop float or sink in water?
A: It depends!
See if you can figure out what is happening in this twist on the classic floating-and-sinking soda can experiment.
What do you do when you don’t have any local or affordable opportunities for professional development?
It's been a few days since my summer break began. I have had a few days to decompress, relax, and think about my next post. I have been planning to write about concept mapping since the end of our first semester. I first recognized the effects of concept mapping in the classroom when I read Shannon Bowen's blog post last December.
