Archive for September, 2006

Canadian bakin’

Thursday, September 28th, 2006

Via CHEMED-L (the chemical education list), here’s an article on a recent Canadian drug bust.

Actually it’s only sort-of a big drug bust. The person charged had some marijuana plants, but the big news is that he was accused of:

selling and possessing “precursor chemicals” for meth

These “precursor chemicals” were the makings of, according to the article, nine million Canadian dollars of meth.

She said the seizure, the result of months of investigation, is the RCMP’s biggest ever in the national capital region.

“It is huge,” Beauchamp [of the Canadian police] said

The chemicals? Red phosphorus and iodine. (Stop laughing.)

Red phosphorus is one of the forms of the element phosphorus. White phosphorus is the other form. It’s nasty stuff, and you’d be well-advised to avoid it.

Red phosphorus, on the other hand, is usually considered non-toxic. Extremely flammable, but non-toxic. Got a match? Well, you’ve quite likely got red phosphorus.

Then there’s iodine. Well, iodine’s just neat stuff. However, it’s actually a lot more toxic than red phosphorus is, in pure solid form. Solutions of iodine, on the other hand, are commonly used as disinfectants – check your local drugstore or your medicine cabinet.

Without making any additional commentary on the various “wars on drugs” and their usefulness, I’ll just say this: If you want to bust someone for meth, bust them for actually having or distributing meth. Busting someone for “precursors”, many of which are extremely common substances, will not lead us anywhere we as a technological society want to go. (See here for what sort of things you could be considered a criminal for having in a certain large US state. Scroll down to see the silliest of the stuff.)

(Edited to add: Or bust the guy for having a ton of highly flammable material in a residential neighborhood, perhaps. But not because it’s a “precursor”.)

Science education as Jeopardy

Friday, September 22nd, 2006

CNN is carrying a small story pointing to a report from the National Research Council on science education for young people. The press release is here.

I haven’t had time to read the full report (352 pages!), but this part of the press release resonates wilh me (bold added by me, for emphasis).

Today’s standards are still too broad, resulting in superficial coverage of science that fails to link concepts or develop them over successive grades, the report says. Teachers also need more opportunities to learn how to teach science as an integrated whole — and to diverse student populations.

A little while ago, I was briefly involved in a workshop whose goals were to try to align the courses of the high school with the courses at the college – making it easier for the high schoolers to transition to our college when they graduate. This gave me some opportunity to talk with some of the high school teachers about what sort of things were in the standards to be covered in high school science classes.

While this National Research Council is about K-8 education, I find that the high school standards suffer from the same problems: too many topics and too few underlying principles. In the mad rush to get through all the bullet points the course is supposed to cover, important concepts receive rather shallow treatment. I remember remarking at the workshop – “Wow, if my freshmen actually understood half of what’s in that list [the standards], all I’d need to do in class is pass out the test.”

My incoming students might have heard the terms “chemical reaction”, “percent yield”, and “equilibrium” Were Alex Trebek to uncover a definition of percent yield on an episode of Jeopardy, many of my incoming students might respond with “What is percent yield?” But they aren’t able to connect these concepts – because they do not see chemistry as a set of ideas linking things together. And, they don’t see science as a way of getting things done. Instead of knowing science, they know Jeopardy.

The National Research Council recommends, for K-8 students, this:

Students should have a wide variety of learning experiences in science classes, the committee said. Those experiences should include conducting investigations; sharing ideas with peers; talking and writing in specialized ways; and using mechanical, mathematical, and computer-based models. Science should be presented as a process of using evidence to build explanatory theories and models, and then checking how well the evidence supports them.

Sounds good to me, but I have my doubts as to whether a lot of this will be implemented. It’s all a matter of cost. All the stuff suggested above costs money – not just in terms of technology, but in terms of personnel. I teach classes for adults who wish to work in the chemical industry – and I try to do a lot of the stuff above with them. For it to work well, the class needs to be small – so you can have meaningful interactions with students on the concepts they’re investigating. You also need adequate technology. For schools that have trouble keeping the buildings from falling apart due to lack of funds (read: poorer districts in my state, for instance), this’ll be a tall order.

Real science is better, but Jeopardy is a lot cheaper. At least in the short term.

North Carolina BBQ – Village Inn in Lumberton

Thursday, September 21st, 2006

My never-ending quest to eat pork barbecue has recently taken me to Lumberton, NC. If you’re headed through Lumberton around dinnertime, you might want to stop and have a bite at the Village Inn Bar-B-Que and Seafood. Here’s what you can expect at the Village Inn

First, don’t expect fancy signs.

[Sign]
They don’t go for fancy neon signs at the Village Inn

Don’t expect a fancy building.

[Outside]
They don’t go for fancy buildings, either.

Do expect excellent hush puppies

[Hush puppies]
Share these with the other folks at your table!

Do expect a good-sized portion of North Carolina light vinegar barbecue, served with slaw and fries.

[BBQ plate]
This is the medium barbecue plate, which cost just under $6.

Don’t expect hash, since you’re in North Carolina.

Village Inn reminds me a little of the barbecue places I would eat at when I was a kid. Shabby cinderblock buildings, decidedly non-fancy decorations and menus, but good food.

[From the table]
No-frills eatin’

You can also get containers of hot or cold barbecue for take-out – just in case you need a shot of pork barbecue for the road, and it’s about as cheap as you’ll find anywhere. At Village Inn, you can get a few pounds of BBQ for what Maurice would charge you for a single Big Joe sandwich in SC.

If you want to try the Village Inn, you’ll find it at 3345 Martin Luther King Jr Drive in Lumberton. If, like me, you’re not from around there, exit I-95 onto highway 74, then follow 74 until you get to highway 21 (which is Martin Luther King Jr Drive). It’s just past the fairgrounds.

Safety tip

Thursday, September 21st, 2006

Dan Holden teaches middle-school socal studies class, and burned a small American flag to get his students to think and write about the flag-burning issue. The story’s here.

As this story takes place in Kentucy, you can imagine what happened. Kentucky has a law against flag desecration, but it’s likely unenforcable due to the Supreme Court ruling that flag desecration is protected speech. So how are the reactionaries going to try to punish Mr. Holden’s brazen attempt to … get students to think about an issue?

The district also alerted city fire officials, who are conducting their own investigation.

“Certainly we’re concerned about the safety aspect,”

Another article says, thankfully, that

… the evidence doesn’t warrant filing a charge of criminal wanton endangerment — causing significant risk of serious injury or death.

So, they were going to try to bust Mr. Holden for “safety” reasons. That’s pretty pathetic, in my book. But there’s a lesson to be learned from this:

If you’re going to burn a small American flag in an effort to get students to think about the flag-burning issue, then make sure to burn said American flag under a properly-functioning fume hood.

F-in Hamburgers!

Friday, September 15th, 2006

Over the Labor Day holiday. we happened to walk by Johnny Rocket’s in Myrtle Beach, where they serve …

[F-in hanburgers]

… F-IN HAMBURGERS!

Having been in this restaurant before, I can tell you that the hamburgers they serve are f-in expensive, and that they don’t taste all that f-in good.

I have to appreciate the truth in advertising, though!

The many phases of iodine

Monday, September 11th, 2006

Iodine is a rather neat element. It’s a nice – if a little boring looking – crystalline solid at room temperature. Chunks of iodine are similar in appearance to things you might find in the bins of rocks at places like Black Market Minerals at Barefoot Landing.

[Solid iodine]
Solid iodine

Iodine is interesting because it is easy to make solid iodine go into the gas state. Plus, unlike many gases, iodine vapor has a distinct purple color and is easy to see. Solid iodine slowly sublimes (goes from the solid state to the vapor) at room temperature. It’s easy to accelerate this process by supplying a little heat.

If the iodine vapor comes into contact with a cool surface, it will deposit (resolidify) on the surface, forming pretty crystals. (A similar thing happens when water vapor comes into contact with a cool surface, although in that case you usually get liquid water.)

To show this, I tried to replicate a picture of a demonstration from one of my older chemistry books. I took some solid iodine and put it into a beaker, then set the beaker on a hotplate. On top of the beaker, I put a watch glass (curved piece of glass that looks something like a lens) and some ice – to provide a nice, cool surface.

[Setup]
Setup

To speed up the production of iodine vapor, I turned on the heat (just a little). You can just barely make out the purple iodine vapor in the beaker.

[A little iodine vapor]
A little vapor is visible

If the hotplate’s temerature gets to about 114 oC (about 237 oF), the iodine will begin to melt, forming a dark purple liquid. The amount of iodine in the vapor state goes up, too!

[More iodine vapor]
More vapor is visible. If you value your nose, keep it away from this vapor.

What’s impressive about this demonstration is the sheer number of phase changes that are going on at once.

[Phases galore!]
Pick a phase, any phase!

At the bottom of the beaker, you have some solid and liquid iodine. Since the hotplate is providing heat energy, you have the solid iodine melting and subliming. The liquid iodine is also evaporating. Near the top of the beaker (and to some extent on the sides of the beaker – which are cooler than the bottom), you have deposition of iodine vapor, forming solid iodine crystals. (It also looks like some iodine may have condensed on the hotter parts of the beaker nearer the bottom, then frozen after the beaker was removed from the hotplate.) That about covers it!

… not counting the ice, that is. The ice at the top of the beaker is melting, removing energy from the iodine vapor as it deposits on the bottom of the cold watch glass.

[Deposited crystals]
Deposited iodine crystals, forming from purple iodine vapor

The crystals formed on the watch glass are flat and shiny – almost metallic in appearance. They’ve grown to look a bit like perverted stalactites.

[Deposited crystals, closer view]
Deposited iodine crystals, closer view

A few words of caution if you attempt this experiment yourself. Iodine may look harmless (it won’t blow up on you – provided you keep it away from combustibles), but iodine solid can cause chemical burns on skin contact, and iodine vapors are very bad for the lungs. This sort of experiment needs a fume hood, and solid iodine shouldn’t be handled directly.

From the department of the obvious

Thursday, September 7th, 2006

News from the department of the obvious: Basic medical instructions hard for most adults, study finds

The subject of the article is how folks have trouble following “health instructions”, which is … not surprising in the least. We do pretty poorly in many areas of science literacy – medical science certainly isn’t an exception.

But here’s the quote that I’m going to fuss about, since I’m your friendly neighborhood chemist.

A consumer may want to know the salt content before buying, but the word salt isn’t on the label.

“Of course, they wrote ‘sodium,’ but that’s a technical term, that’s a chemistry term,” [Dr. Rima] Rudd said. “You don’t sit at the family table and say, ‘Pass the sodium please.”‘

Well of course you don’t ask someone to pass the sodium at the dinner table. Pure sodium is a soft, metallic element that reacts violently with water. It would be a decidedly bad thing to pass around at the family table. The stuff you pass around at the dinner table is a sodium-containing compound called sodium chloride.

Plus, “sodium” is hardly a more technical term than “gold”, “silver”, “iron”, or “oxygen”.

“They’re writing things at a level in the health field that is very difficult for the general public to work with,” Rudd said.

While I’d certainly agree that information leaflets that come with prescription drugs are written in a language that is difficult for someone without medical training to understand, I do not think the same thing applies to “sodium” on the side of a soup can. Anyone who makes it out of high school without enough knowledge to know a few basic things about what common table salt contains has been done a disservice.

Friday cat: Too hot for you!

Friday, September 1st, 2006

Rusty has a message for you.

[Rusty]
Rusty: Why yes, I really am that hot.

Click the image to enlarge.

For more feline friends, check out The Friday Ark.