Sunday, February 24, 2008

Fizz, Bubble & Flash


I reserved this book through my library's website a while back but just took a look at it the other day. At first glance, it looks like a book for younger children (the age range listed on the back is 8 and up). But with its lively, clear explanations of all the elements and families of the periodic table and its nicely-laid-out experiments, including variations on demonstrations I've seen elsewhere plus some that are new to me (such as one that tests zirconium-based underarm anti-perspirant on aluminum foil), I'm thinking of buying a copy to keep around for my own teens. Author Anita Brandolini is a chemistry professor at Ramapo College who tested out the activities on kids at the Liberty Science Center in New Jersey (a museum which my family has enjoyed on trips with the grandparents). My only beef: in general the illustrations are cute, but the drawings of molecules don't successfully convey the idea of their structure in three-dimensional space.

Wednesday, February 20, 2008

Comic Book Elements



"OK, 103 -- Now you're going to turn him into pure copper!"

Coughs, colds and catching up have kept us from doing more experiments. Hopefully we'll get back to it soon.

In the meantime, while searching for info on Ferrofluid and Magnetic Slime, I came across this nifty site. The Periodic Table of Comic Books links each element to its appearance on the printed page. From the University of Kentucky Department of Chemistry!

Saturday, February 16, 2008

Access to Chemistry at Oxford


Oxford University in England has joined the list of colleges offering FREE online courses to the public. Their Access to Chemistry website "provides an excellent resource for prospective applicants to learn more about Chemistry at Oxford from anywhere in the world."

When you click on Pre-University Course, you can page through teaching material based on the book "Chemistry, Matter and the Universe" by Richard E. Dickerson and Irving Geis -- complete with helpful animated illustrations. Here's the introduction:
Many reasons can be given for studying chemistry, ranging from, "It is an intellectual adventure," to "I can make a good living at it," or even "It is required for graduation."

But the most valid response is simple. Chemistry is the study of how matter behaves. We have only one world in which to live. If we want to know how we can change it and what we cannot alter, or even simply to appreciate what we already have, then we must know how it works.

Chemistry is the subject that tells us this. Physics may teach us fundamental facts about elementary particles, matter, and energy, but it stops short of drawing conclusions about how the different kinds of matter around us change and react. Biology describes the large-scale behavior of organisms, which at their core are elaborate chemical systems. Some of the most fruitful advances in biology in the past two decades have come from a thoroughly chemical approach. If we can expand the concept of chemistry beyond our present limited and inadequate knowledge, then biology fundamentally is the highest form of applied chemistry. If chemistry is the study of how matter behaves, we must not forget that we, ourselves, are an integral part of this material world.
This is all part of Oxford's Virtual Chemistry Virtual Laboratory, which includes a 3DChem (a molecule of the month website), LiveChem (a library of nearly 300 videos), and a Webcast Lecture Series of courses such as Dr. Hugh Cartwright's Entertaining Chemistry. Looks to be an excellent resource!

Thursday, February 14, 2008

Happy Valentine's Day!



Do these hearts look strangely familiar to you?




H2O2



Hydrogen Peroxide



Ozone


Oxygen

Courtesy of Muse, the world's best magazine for tweens!



February's cover features "Oxygen: A Love Story" -- an excerpt from Gabrielle Walker's new book, An Ocean of Air: Why the Wind Blows and Other Mysteries of the Atmosphere, which tells how Earth's atmosphere developed.

I just loved the way it looked!

Tuesday, February 12, 2008

Precipitation


No, it's not raining or snowing (at the moment). Last week we did two (of four) small demonstrations from The Joy of Chemistry to illustrate how different conditions affect whether a solid will go into a liquid in solution or fall back (precipitate) out. Here, in my non-official lab report style, are our results:

Demo 1: Baking Soda
Effect of Temperature and Amount

Materials

Baking soda
Water
Glass measuring cup
Plastic spoon

Directions

1. Add a pinch of baking soda to 2 cups of water. Stir to dissolve.
2. Keep adding pinches (about 10-15) until solution starts to become cloudy and baking soda fall to the bottom.
3. Microwave glass for 30 seconds, until warm.
4. Is solution clear? Does precipitate dissolve with stirring?

Observations

It took 45 "pinches" of baking soda to get enough precipitate on the bottom of the cup to notice. The water was only barely cloudy. Measuring out the baking soda in 1/4 or 1/2 teaspoon amounts -- or using less water -- would make the process go faster.

Heating the cup in the microwave even a small amount did allow all the baking soda to go into solution.

As a demo for kids, less than impressive.








Demo 2: Chalk in Water and Vinegar
Effect of Condition of Salt and of Solution

Materials


Prang* white chalk
4 plastic cups
Water
Vinegar

NOTE: Prang brand chalk worked great! (Not like our first attempts with other chalk.) Still haven't found it for sale locally, though -- I found some in a school I visited and borrowed a piece.

Directions

1. Break chalk into 4 pieces.
2. Crush 2 teaspoons of chalk.
3. Fill 2 drinking cups with 1 cup of water. Fill other 2 cups with 1 cup of vinegar.
4. Place 1 whole piece in first cup of water. What happens?
5. Place 1 teaspoon crushed chalk in water and observe. Stir. What happens?
6. Repeat with chalk and vinegar. What happens?

Observations



Whole piece in water: Nothing
Powdered chalk in water: Water got very cloudy
Whole piece in vinegar: Chunks of chalk broke off in layers and floated to the top!
Powdered chalk in vinegar: First it foamed up. After a few minutes, chunks started bobbing up and down!

(Took some lovely video of the bobbing effect which came out sideways. When I can convert the MOV file to AVI so I can rotate it in Windows Movie Maker -- or get more chalk and re-shoot it -- I will post it!)

Wednesday, February 6, 2008

New and Improved About.com Chemistry Page


Today I'm making up a worksheet of experiments to do later in the week about solutions and precipitates, based on our "spine," The Joy of Chemistry. While I find the book helpful in organizing my lessons (and, of course, providing all my information), it hasn't worked for us as a read-aloud. So what I do is go through the chapter I want to cover, find the demonstrations that I think we can do (based on availability of materials and risk level) and type them up. Surprisingly, despite the analogy the authors make to "The Joy of Cooking," the "recipes" in their book are integrated right into the text. So unless you're reading it surrounded by your fully-appointed and ready-to-use laboratory, it's a little hard to do the demonstrations just using the book. To make them usable for us, I've been putting them into recipe form -- Explanation, List of Equipment and Ingredients, Directions. I told both co-author Monty Fetterolf and his publisher's PR person that if they don't come out with a new edition, I'm going to write my own companion volume when I'm done!

One other thing I've been doing is finding similar, related experiments to add to, modify or replace some of the demonstrations in the book that I feel could use improvement (or just can't resist tinkering with). My main source for this information has been Anne Helmenstine's Chemistry section at About.com. I just scooted over there to see what she had on our upcoming projects and saw the site has gotten a makeover. It's cleaner looking, and the ads have been toned way down, making it easier to find what you want. The current lead story is about making a "Do It Yourself Chemistry Lab." One interesting question discussed: "Is It Safe to Use Kitchen Glassware for Chemistry?" Helmestine writes:
I remember a chemistry experiment in analytical chemistry class where we were asked to take a piece of glassware from the storeroom, get it as clean as we could, and then the instructor rinsed it with acid and water and showed us the spectrum of the stuff that was still on the glass. As you would imagine, there were heavy metals and some dangerous organics. He was trying to illustrate that even 'clean' glassware isn't inert and can mess up an analysis, but it also went a long way to explaining why we shouldn't make coffee in the lab. Using dishes for chemistry projects isn't the same thing, but it may not be safe.
Her conclusion? Yes and no. "If I make slime or a smoke bomb I'll use dishes, but I'll be careful to rinse them immediately so that no one accidentally eats borax or saltpeter ... but there are exceptions. For example, I wouldn't make green fire in cookware. "

I know a certain 12-year-old that will appreciate my saving those particular links.

Update: Anne Helmenstine left a nice little comment to this post. And I couldn't asking why the little white dish in the green fire photo above looked so much like a Corningware ramekin. Her reply:
Um... (confession time)... that's because it is a Corning ramekin. I think what I said was I wouldn't use ceramic cookware, not that I didn't, lol. When I tried that project, I did not expect the methanol in the Heet to burn quite that hot. I'm surprised the ramekin didn't shatter. For future tests, I used a stainless steel mixing bowl.
Just so you know.