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.

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...

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...

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.

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?

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

1. Line the bottom of the container with the aluminum foil.
2. Add the tarnished item.
3. Pour in sufficient steaming hot water to cover your tarnished silver.
4. Add equal amounts of salt and baking soda (about 2 teaspoons each for silverware, more if you are filling a sink).
5. 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.
6. 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.

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.

November 5^th is Léon 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.

I've got a new video showing you how to make your own pH paper test strips. It's very quick and easy. Try it...

On November 4, 1943, the X-10 nuclear reactor began operations. This reactor was the first reactor built to produce plutonium for the Manhattan Project. The reactor consisted of a 24 foot cube of graphite slabs surrounded by a thick concrete radiation shield. There were 1,248 horizontal holes drilled into the graphite to hold slugs of uranium fuel. These slugs would remain in the reactor to emit and absorb neutrons to convert uranium-238 into plutonium-239. After a period of time, operators would push an new uranium slug into the hole and shove the plutonium rich slug out the back for processing. The plutonium would be extracted and sent on to the Los Alamos facility.

The X-10 reactor was shut down in 1963 and declared a National Historical Landmark in 1965. The reactor face is still open to the public and a must see to anyone who visits Oak Ridge National Laboratory. Find out what else occurred on this day in science history.