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Nearly text free (and loving it)

I used the following presentation to go over how and why to balance chemical equations with my 9th graders:

Balancing Chemical Rx

View SlideShare presentation or Upload your own. (tags: chemistry chemical)

The concept itself isn't complex, but instruction often gets bogged down in providing students with a list of specific steps to follow (First, count the number of atoms, second...).  Suddenly it goes from being a simple concept to a complex procedure which almost requires students to actually memorize the specific steps.

I started with a quick review of the Law of Conservation of Mass (matter cannot be created or destroyed, though it can be rearranged), and then jump into the teeter-totter analogy to explain why unbalanced equations violate this law. We then worked through some examples together.

With each repetition I increasingly withdrew my support. By the third example students could go through and balance equations without me around. They didn't need to follow a prescribed set of steps. They knew that you can''t have more oxygen atoms on one side of the reaction than the other and worked through to figure out the balanced equation.

As for technological savvy to create the edited images of the sign: I did all image editing in PowerPoint itself; which is to say it's pretty basic and pretty crude.

Resources

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Universal Declaration of Human Rights

A beautiful typographic video of the Universal Declaration of Human Rights put out by the Human Rights Action Center:

The Universal Declaration of Human Rights from Seth Brau on Vimeo.
It amazed me how large a percentage of the world doesn't enjoy the basic rights set forth in this declaration. In fact, even the United States may not allow for its citizens to enjoy all the rights laid out by the declaration.

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Video from vimeo :: via NOTCOT.org

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Awesome Video of the Week, Vol. 4

Amazing slow motion video of a lightning strike:

Most people have an emotional response to lightning. Growing up, that emotion for me was fear¹. As I got older, the fear gave way to respect, awe, and wonder. Indeed, staring out at an approaching thunderstorm on a warm summer night, watching the constant flashes of light, for me is one of the most mesmerizing sights.

In super slow motion you can actually see the streams of negative charges (often called a stepped leader) branching down from the cloud seeking out the more positively charged surface of the Earth. Generally this happens so fast the human eye can't pick it up. Once one of the branches of negative charges makes contact with the positively charged ground (or tree, or house, or whatever) the circuit is completed, releasing the stored electrical energy and creating the lightning bolt we're all familiar with.

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LHC Day!

Today marks the first time the Large Hadron Collider will attempt to circulate a particle beam. This new tool in the belt of particle physicists should help prove/disprove some current grand unified theories, including the existence of the Higgs Boson, thought to be responsible for giving mass to particles.

While some people have been worried the LHC will cause some crazy reaction that will end in the destruction of the Earth (say, via a black hole), Cory Doctorow in a post at Boing Boing quoted a physics who said of the chances of the LHC destroying the Earth: "Look, it's a 10^-19 chance, and you've got a 10^-11 chance of suddenly evaporating while shaving."

In honor of this grand event, I post below the LHC Rap, which is a surprisingly good song about the LHC. If you weren't listening too closely, you could almost mistake it for a Digable Planets song (almost).

To learn more, check out CERN's home for the Large Hadron Collider.

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Awesome Video of the Week, Vol. 2

Time lapse of slime molds and various mushrooms growing:

Slime molds are crazy organisms. They live animal-like lives for much of the time, but will eventually "settle down" when it's mated (if you can even call it that) and then release spores as if they were fungi. Some experts have argued that slime molds should be their own kingdom since they are so unique.

It's a good illustration of how science is a construct of our own species. We do our best to make observations and organize the universe into distinct categories. Sometimes, however, there are things that don't fit cleanly into our categories. These often lead to debates between groups of scientists, who eventually reach a general consensus based upon the best information available. Often when new information is discovered, we learn we had it backwards or even find out we really had no clue what was going on in the first place. All of which is OK, since it's all progress. 🙂

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Awesome Video of the Week, Vol. 1

In addition to my interesting finds series, I'm starting this series which will include a video of something I found compelling, awesome, or interesting each week. They may be videos that are educationally useful or they may just be too awesome to not share with the world.

This first video's narration is in Japanese, and I don't know what's being said, but it still fits into both of those categories: educational and awesome (crazy awesome): The Goblin Shark

Besides the immediate (for me) connection between the Goblin Shark and the alien from the Alien movie series, this video can lead to some interesting discussions in a science classroom. Why did this species of shark evolve its special jaw mechanism? What type of terrain/environment/other factors led this crazy jaw mutation to be selected over the more standard type of shark jaw?

Taken further, this could lead into students "designing" their own crazy creatures, with the caveat that whatever crazy appendages or features their creatures have must be defended with an explanation of how these specific mutations would provide the creatures with evolutionary advantages over other animals competing for resources in the same ecosystem. You might even be able to work this type of assignment into using this game, but I haven't worked out the specifics of that quite yet.