About Chemistry

On This Day in Science History - November 8 - Rorschach Ink Blots

2009-11-08T00:05:16Z

What do you see in this picture?
Tests show most people will say "A bat". Looks more like a fox face to me. Supposedly, there is no wrong answer.
November 8^th is Hermann Rorschach's birthday. Rorschach used this inkblot and nine other inkblots to aid with his psychiatric practice. The Rorschach Test was intended to give insight to the workings of the patient's thought processes. While the test is still popular, controversy exists among psychologists as to whether or not the test actually shows anything at all.

Find out what else occurred on this day in science history.

On This Day in Science History - November 8 - Rorschach Ink Blots originally appeared on About.com Chemistry on Sunday, November 8th, 2009 at 00:05:16.

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High-Tech Spit Balls

2009-11-07T10:18:59Z

Here's an interesting application of what I am guessing is sodium polyacrylate, the polymer used in disposable diapers, polymer gel balls and fake snow. According to a post over at OhGizmo!, Edmund Scientific is offering a version of these polymer balls for use as spit balls. Edmund Scientific says their spit balls with "Slip, Slide, Bounce & Explode" -- all essential qualities for a good spit ball. Whether students will trade in the traditional chewed tissue spit balls for the clear polymer balls remains to be seen. It's time for some experimentation, don't you think?

High-Tech Spit Balls originally appeared on About.com Chemistry on Saturday, November 7th, 2009 at 10:18:59.

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On This Day in Science History - November 7 - Tacoma Narrows Bridge

2009-11-07T00:05:40Z

On November 7, 1940, the bridge spanning Puget Sound across the Tacoma Narrows in Washington state dramatically collapsed. The bridge opened on July 1, 1940 as the third longest suspension bridge in the world. Almost immediately, the bridge was nicknamed "Gallopin' Gertie" because of its sway due to the wind. The state hired an engineer to propose methods to settle Gertie's galloping tendencies. They concluded their study on November 2, 1940 and recommended a couple of options to fix the problem. Unfortunately, the bridge didn't wait for the repairs.

On the morning of November 7, the winds were pretty strong and the bridge swayed more than usual. As the wind speed built up during the morning, the swaying approached the resonant frequency of the bridge itself. The bridge span began to jump and sway until it ripped itself apart at 11:00. Because of the long period of time it took to reach the breaking point, local camera shop owner Barney Elliott was able to film the collapse. This film is still shown to students of architecture, physics and engineering.

There was only one casualty to the collapse. The man in the film running from his car was named Leonard Coatsworth. Mr. Coatsworth attempted to cross the bridge but abandoned his car and daughter's cocker spaniel Tubby. Tubby would not leave the car even when others attempted to rescue him and went down with the bridge.

Find out what else occurred on this day in science history.

On This Day in Science History - November 7 - Tacoma Narrows Bridge originally appeared on About.com Chemistry on Saturday, November 7th, 2009 at 00:05:40.

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New Periodic Table Quiz

2009-11-06T11:58:37Z

While I was organizing element quizzes I noticed I had never offered a periodic table quiz. If you're taking a chemistry class you're practically guaranteed to be tested on this information, so I made up a quick periodic table self-test. This 10-question multiple choice quiz focuses on how well you understand the organization of the periodic table and how it can be used to predict trends in element properties. Can you get a perfect score? Take the quiz...

New Periodic Table Quiz originally appeared on About.com Chemistry on Friday, November 6th, 2009 at 11:58:37.

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Element Quizzes

2009-11-06T10:09:55Z

You do a lot more problem-solving than memorizing in chemistry, but learning the element symbols and the names of the first several elements is common test fodder (because it's so useful). It's also important to know how the periodic table is set up and how you can use periodicity to predict element properties. One way to make sure you're on track regarding the elements is to quiz yourself. With this in mind, I've collected the most popular/useful element quizzes in one place. You can review the concepts and then test yourself (without actually getting a grade). Take a quiz...

Element Quizzes originally appeared on About.com Chemistry on Friday, November 6th, 2009 at 10:09:55.

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On This Day in Science History - November 6 - Yeast Fermentation

2009-11-06T00:05:40Z

November 7^th marks the passing of Swedish biochemist, Hans von Euler-Chelpin. He was awarded the 1929 Nobel Prize in Chemistry with Arthur Harden for their investigations into the process of fermentation and yeast enzymes.

Brewers use yeast to convert glucose (sugar) into carbon dioxide and ethyl alcohol. People have been using yeast for centuries for fermentation but the process was not fully understood. Eduard Buchner identified the yeast enzyme called zymase when he removed all cells from the yeast and still managed to produce fermentation. He would win the 1907 Nobel Prize for this discovery. Harden later showed zymase was made up of two different varieties and Euler-Chelpin discovered the complementary enzyme, cozymase that was responsible for the production of carbon dioxide in the process.

Find out what else occurred on this day in science history.

On This Day in Science History - November 6 - Yeast Fermentation originally appeared on About.com Chemistry on Friday, November 6th, 2009 at 00:05:40.

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This Day in Science Fiction History - Invention of the Flux Capacitor

2009-11-05T13:40:15Z

You know how every day I've been posting a collection of factoids about significant events in science history? Of note today is an event which hasn't actually occurred (though feel free to remedy this). November 5, 1955 was the date that Doctor Emmet Lathrop Brown slipped from standing on the toilet to hang a wall clock, hit his head on the bathroom sink, and had a vision of how he could design a flux capacitor, which (as we all know) made time travel possible. Quiz time... what movie is this from?

This Day in Science Fiction History - Invention of the Flux Capacitor originally appeared on About.com Chemistry on Thursday, November 5th, 2009 at 13:40:15.

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Silver Polish without Polishing

2009-11-05T11:56:49Z

I wanted to take a before/after photo of what you can expect when you use electrochemistry to polish silver, but... all I had in the house that was silver were some chains and one big silver bowl that has been black since the 1980s. I went with the bowl, which produced a picture that needs some explanation. What you see in this photo is the bottom of the bowl (silver again) and the sides/top (black). I filled the bowl halfway with hot water, sprinked in some salt and baking soda, and added a piece of aluminum foil. If you have silver cutlery, candlesticks, holloware, etc. that needs cleaned (even if it's totally darkened with tarnish), here's what you do:

Electrochemistry Silver Polish Materials

pan large enough for your items (or the sink)
hot water
salt
baking soda
aluminum foil

Dip the Silver

Line the bottom of the container with the aluminum foil.
Add the tarnished item.
Pour in sufficient steaming hot water to cover your tarnished silver.
Add equal amounts of salt and baking soda (about 2 teaspoons each for silverware, more if you are filling a sink).
Allow about 5 minutes for the reaction to remove the tarnish. If you don't see any effect, you may want to add more salt/baking soda and make sure some part of the silver is in contact with the foil.
Rinse the silver under clean water and dry it with a soft cloth.

Note that silver-plated items may not get completely clean using this dip (or any silver polish) because it's possible that the thin layer of silver may be so tarnished that it is removed. Having said that, I think this bowl is plated rather than solid silver, and it looks a thousand times better than before using the dip.

Silver Polish without Polishing originally appeared on About.com Chemistry on Thursday, November 5th, 2009 at 11:56:49.

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Periodic Table Tie and Caffeine Silk Tie

2009-11-05T11:05:40Z

A while back I posted about a periodic table sweater and got an overwhelming e-mail response asking where the sweater was available for sale. The sweater is one-of-a-kind, but I've been keeping an eye out for fashionable chemistry apparel that you can get. I'm not a guy, so I don't have much use for ties, but if I did wear them I'd add a periodic table tie or caffeine molecule tie to my wardrobe.

Do you know about other chemistry-related clothing or accessories available online? If so, you're welcome to post a reply.

Periodic Table Tie and Caffeine Silk Tie originally appeared on About.com Chemistry on Thursday, November 5th, 2009 at 11:05:40.

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On This Day in Science History - November 5 - L�on Teisserenc de Bort

2009-11-05T00:05:12Z

November 5^th is L�on Teisserenc de Bort's birthday. He was a French meteorologist best known for the discovery of the layer in the atmosphere known as the stratosphere. He was a pioneer of the unmanned weather balloons carrying instruments to collect and record data such as temperature, pressure and wind speed. Typically, as you increase altitude, the temperature falls rather quickly. He discovered a boundry layer of the atmosphere approximately 7 miles up where the temperature would stop decreasing and would remain constant as the altitude increased. He concluded there were two regions of the atmosphere. The first 7 miles was called the troposphere ("sphere of change" in Greek) where the weather was constantly changing and stirring up the different gases in air because of the temperature differences in the air. After 7 miles, he reasoned the gases in the air would layer themselves, heaviest to lightest in strata. He named this section the stratosphere.

Find out what else occurred on this day in science history.

On This Day in Science History - November 5 - L�on Teisserenc de Bort originally appeared on About.com Chemistry on Thursday, November 5th, 2009 at 00:05:12.

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