A free workshop for educators on December 9th from the National Science Digital Library:

This Web Seminar will focus on dynamic online resources you can use to teach your students about the chemistry of water through the NSDL Chemical Education Digital Library. Join presenters Dr. John Moore, W. T. Lippincott Professor and director of the Institute for Chemical Education, and Dr. Lynn Diener, Assistant Professor, Mount Mary College in Milawaukee, Wisconsin and guests Jon Holmes, Editor of Journal of Chemical Education Online and Dr. James Skinner, Chemistry Professor at the University of Wisconsin-Madison for this seminar for educators of grades 9-12.

Register for this free seminar

Learn more about NSDL NSTA Web Seminars

Hey hey, I’ve got a twofer in the current issue of the Physics Teacher!  One is my article on the chemistry behind the saltwater battery. The other is an article on blogs that physics teachers can use.  I’ll post the full blog article (the published one was cut quite heavily) a little later!circuit_th

Here’s the crux of the saltwater activity:  When you connect cups filled with salty water together, you can make a current strong enough to ring a buzzer or light an LED.  Neat!  This article explains the electrochemistry behind this popular activity so that physics teachers can know enough chemistry to understand a lot of the weird behavior that they see.  I’m a physicist, so I don’t know much chemistry.  So this paper is kind of neat in that it’s a joint venture between myself and my dad, retired physical chemist Dennis Chasteen.  My mentor Paul Doherty is also a co-author.

The construction of the cell is largely borrowed from the Exploratorium’s Square Wheels book (thanks to master tinkerer Don Rathjen!)

You can download a PDF of the article here.

Here are some supporting materials on my mentor and coauthor (Paul Doherty’s) website.

One of the NSDL blogs — Exemplary Resources for Middle School Math and Science — just posted a very nice list of several places you can find information on science & sports for use in your classroom:

These resources take an in-depth look at how chemistry and technology have had a huge impact on all kinds of sports – from golf to paintball and in addition, follow the theme of this year’s National Chemistry Week (October 19-25, 2008) – Having a Ball with Chemistry!

Chemistry: Making It Real
The resources selected for this publication from the NSDL Middle School Portal will help your students understand chemistry at work, using examples that will spark their interest. A basic understanding of chemistry concepts and terminology will prepare them for more abstract studies in chemistry in their high school years and beyond.

Sport Science
The Exploratorium explains the science behind cycling, skateboarding, surfing, hockey, and baseball. Articles, interviews, interactive simulations, video clips, and activities for students provide an in-depth look at all these sports.

Golf Balls
Since the late 1800s, chemists have been called on to find ways to produce lighter, faster, and durable golf balls. This site traces the chemistry that has transformed the ball and promises to create a ball that will “soar like a cruise missile, hit the ground at a very shallow angle, and roll for up to 40 yards on hard ground.”

Artificial Snow
Towns that depend on skiing for their income watch the skies for signs of snow. If it doesn’t come in sufficient amounts, they can call on companies that make snow. Sometimes snow is needed on movie sets or other indoor sites. Various methods of making snow for different purposes are described here.

Paintball: Chemistry Hits Its Mark
The first paintballs were fired by foresters and ranchers to mark trees and cattle. In the 1980s, someone got the idea that it would be more fun to fire paintballs at people than at trees and cows. Thus the sport of paintball was born. In this article from ChemMatters, learn how the one billion paintballs manufactured each year are a product of chemistry and engineering.

There’s always a lot to learn when you start teaching.  But this new teacher’s story was particularly striking to me.  When she just started teaching, she was fresh out of the Peace Corps in West Africa, and this left her little prepared to teach chemistry in a portable classroom with, among other things, no proper way to store lab chemicals.  Listen to this new teacher’s story (“Huh?”) in the latest episode of my Science Teaching Tips podcast.

A teacher asked for a good experiment to show 8th graders that gas has mass.  “We have used balloons in the past,” she says, “but some of the kids still don’t make the connection.”

Paul Doherty replied:

I like to get a big weather balloon from a surplus store , inflate it until it is 1 meter in diameter or a little more and then a second balloon that is deflated.

Have a kid stand and throw the empty balloon at the back of their head…they feel almost no force.

Then throw the full one. It packs a noticeable punch due to the mass of moving air. the mass approaches a kilogram.

Of course you cannot weigh it using a scale due to buoyancy. You can only feel the mass by accelerating it or decelerating it.

And Eric Muller added:

Get some dry ice. It is solid Carbon Dioxide and it has noticeable mass. Lots of stores around the bay area sell dry ice. Many Safeways, Albertsons, bait shops, liquor stores, ice distributors and welding supply companies carry dry ice.

Weigh (or Mass) a chunk of dry ice. Put the chunk in a plastic bag and tie it off. It will sublimate and turn into a gas. The bag will expand noticeable. A solid, 44gram chunk of dry ice (that’s the size of a couple of fingers) will expand to around 22.4 liters of gas.

Gas has mass!

soda_bubbles_macro.jpgHi everyone, I posted an episode to my podcast, Science Teaching Tips.

Click this link to check it out:
31. Carbon dioxide – Its a gas!

TI staff educator Eric Muller shows me how to carbonate my tongue. Blech!
More of Eric Muller’s activities: www.exo.net/~emuller

– Stephanie

Another episode of my podcast, Science Teaching Tips!

Ice Scream

TI staff educator Eric Muller demonstrates a “cool” thing to do with dry ice, and it even relates to the standards!
More of Eric Muller’s activities: http://www.exo.net/~emuller