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Thanksgiving Chemistry

Sun, 22 Nov 2009 08:12:21 +0000

Thanksgiving is all about being thankful, but one of the things Americans are thankful for on the holiday is having a good Thanksgiving dinner with family and loved ones. There's a lot of chemistry in the whole Thanksgiving dinner part of the holiday, plus there are a variety of fun chemistry projects you can do that relate to Thanksgiving. Here are some ideas to get you started.

Thanksgiving Chemistry originally appeared on About.com Chemistry on Sunday, November 22nd, 2009 at 08:12:21.

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On This Day in Science History - November 22 - Krebs Cycle

Sun, 22 Nov 2009 00:05:33 +0000

November 22 marks the passing of Hans Adolf Krebs. Krebs was a German chemist who was awarded the 1953 Nobel Prize in Medicine for the discovery of the citric acid cycle or the Krebs cycle. The Krebs cycle is a series of chemical reactions that take place in cells where food is broken down into carbon dioxide, water and energy. The reactions take place in the mitochondria of cells as part of the process of cellular respiration. At the beginning of the cycle, an acetyl group broken down from food combines with a four-carbon molecule called oxaloacetate to make a six-carbon compound, citric acid. The citric acid molecule is rearranged and stripped of two of its carbon atoms during the process releasing carbon dioxide and 4 electrons. At the end of the cycle, a molecule of oxaloacetate remains, which can combine with another acetyl group to being the cycle again.

Find out more about Hans Krebs and what else occurred on this day in science history.

On This Day in Science History - November 22 - Krebs Cycle originally appeared on About.com Chemistry on Sunday, November 22nd, 2009 at 00:05:33.

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Colored Fire Video

Sat, 21 Nov 2009 08:53:09 +0000

If you've been wanting to make colored fire, but weren't sure quite what to do or what to expect, then watch my new green fire video tutorial. You can make the fire in pretty much any color you like simply by substituting one of the other colored fire chemicals for the boric acid used to make green fire.

If you have suggestions for other chemistry videos you'd like to see, please post a reply describing your idea.

Colored Fire Video originally appeared on About.com Chemistry on Saturday, November 21st, 2009 at 08:53:09.

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On This Day in Science History - November 21 - Indium

Sat, 21 Nov 2009 00:05:32 +0000

November 21^st is Hieronymus Theodor Richter's birthday. Richter was a German chemist who discovered the element indium with Ferdinand Reich. They discovered the element using the relatively new technique of spectroscopy. When a substance is heated, the light it emits can be passed through a prism to separate individual bands of color that are unique to each element. They isolated a substance that turned out to be a new element that gave off a vivid indigo spectral line and named it indium.

Indium is a shiny, silver-white metal with element number 49. It is a very soft metal that when bent emits a 'cry' that is a high pitched squeak when bent. It is commonly used in semiconductor electronics, mirrors and as a coating for high performance bearings. It's most common use today is in liquid crystal displays and touchscreens.

Find out more about Richter and what else occurred on this day in science history.

On This Day in Science History - November 21 - Indium originally appeared on About.com Chemistry on Saturday, November 21st, 2009 at 00:05:32.

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Why Is Your Turkey Dry?

Fri, 20 Nov 2009 10:01:15 +0000

While watching the History Channel, I learned why I haven't made a dry turkey. The secret of my success? Impatience. My family circles the roasting turkey, ready to pounce the instant it hits the minimum cooking temperature, which in my house is 170°F. Depending on what you read, the safe/optimum cooking temperature is 160°F to 180°F. The minimum temperature is supposed to protect you from bacteria (mainly Salmonella) and parasites (eww). If you shoot for the lower temperature then the dark meat of the turkey (the legs and thigh) will be tough and underdone. If you aim at the upper end of the temperature range then the dark meat may be fine, but the white meat will be tough and dry. According to the History Channel, at 170° the proteins that comprise turkey meat start to break apart, which produces a tender meat. However, at 180° the proteins start to coagulate, toughening and drying your bird.

Did you know you can't tell how done your turkey is by whether the meat is white or pink? The bones of young turkeys (and chickens) are porous, allowing hemoglobin to leech into the meat and tinge it pink, even if the meat has been thoroughly cooked. Smoked or grilled turkeys are especially likely to have pink meat when done.

Temperature can affect the quality of your turkey in a way you probably can't control, too. The rate at which turkeys were chilled when they were processed affects the meat texture. Similarly, you may expect differences in meat between fresh turkeys and thawed turkeys that were frozen.

Why Is Your Turkey Dry? originally appeared on About.com Chemistry on Friday, November 20th, 2009 at 10:01:15.

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On This Day in Science History - November 20 - Karl von Frisch and Bees

Fri, 20 Nov 2009 00:05:54 +0000

November 20^th is Karl von Frisch's birthday. Frisch was an Austrian biologist who investigated the behavior and senses of bees. He found bees can see in the ultraviolet spectrum of light and are sensitive to polarized light. He also determined the meaning of the 'wiggle dance' that bees perform to inform other bees the distance and direction to sources of pollen and nectar. His investigations into bee life would earn him part of the 1973 Nobel Prize in Medicine. This Prize was the first to deal with the interactive study of humans and animals and help gain recognition of social behavior as a biological science.

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

On This Day in Science History - November 20 - Karl von Frisch and Bees originally appeared on About.com Chemistry on Friday, November 20th, 2009 at 00:05:54.

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On This Day in Science History - November 19 - John Vane

Thu, 19 Nov 2009 00:05:30 +0000

November 19^th marks the passing of John Vane. Vane was a British biochemist who spent his career studying prostaglandins. Prostaglandins are compounds that regulate many different functions in the body. Vane developed a test called teh dynamic bioassay that identified and measured the substances that make up blood and other fluids of the body. Using this test, he discovered prostaglandins are produced by several tissues and organs and their effect was short ranged, typically affecting the area near where they were produced. One of the experiments he performed found that aspirin inhibited the production of prostaglandin that causes inflammation. This demonstrated definite physiological evidence to support the use of aspirin as an anti-inflammatory medicine. This discovery would also earn him a third of the 1983 Nobel Prize in Medicine.

He also discovered another prostaglandin called prostacyclin that was important to the process of blood coagulation. Prostacyclin is used to prevent blood clotting during surgeries and also to dissolve blood clots that may cause heart attacks and strokes. Find out what else occurred on this day in science history.

On This Day in Science History - November 19 - John Vane originally appeared on About.com Chemistry on Thursday, November 19th, 2009 at 00:05:30.

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Wordless Wednesday - Make a Fake Neon Sign

Wed, 18 Nov 2009 07:23:51 +0000

Do you long for a neon sign with a customized message? You can make a fake neon sign inexpensively using easy-to-find materials. This is a great crafty science project!

Wordless Wednesday - Make a Fake Neon Sign originally appeared on About.com Chemistry on Wednesday, November 18th, 2009 at 07:23:51.

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On This Day in Science History - November 18 - Third Law of Thermodynamics

Wed, 18 Nov 2009 00:05:09 +0000

November 18^th marks the passing of Walther Nernst. Nernst was the German physical chemist who introduced the third law of thermodynamics. The laws of thermodynamics describe the transport of energy and work in systems and are fundamental to all science disciplines. The third law says that it is impossible for a system to reach a temperature of absolute zero. It states that as a system approaches absolute zero, all processes cease and the entropy of the system approaches a minimum value.

Nernst made many contributions to electrochemistry, solid state chemistry and photochemistry in addition to his work in thermodynamics. Find out what else occurred on this day in science history.

On This Day in Science History - November 18 - Third Law of Thermodynamics originally appeared on About.com Chemistry on Wednesday, November 18th, 2009 at 00:05:09.

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Substituting Baking Powder and Baking Soda

Tue, 17 Nov 2009 15:36:38 +0000

Holiday baking can be more of a challenge if you discover all your baking soda got used up for baking soda volcanoes and invisible ink. If you have baking powder, it will save you a trip to the store. If your problem is being out of baking powder, you can make your own using baking soda and cream of tartar. Here's how to make the substitutions:

Using Baking Powder Instead of Baking Soda

You need to use 2-3 times more baking powder than baking soda. The extra ingredients in the baking powder will have an effect on the taste of whatever you are making, but this isn't necessarily bad.
Ideally, triple the amount of baking soda to equal the amount of baking powder. So, if the recipe called for 1 tsp baking soda, you would use 3 tsp baking powder.
What I do is compromise... I use twice the amount of baking powder as baking soda (add 2 tsp of baking powder if the recipe calls for 1 tdp baking soda), plus I omit the salt (which adds flavor but also affects rising in some recipes).

Making Baking Powder

You need baking soda and cream of tartar to make baking powder.
Mix 2 parts cream of tartar with 1 part baking soda. For example, mix 2 tsp cream of tartar with 1 tsp baking soda.
Use the amount of baking powder called for by the recipe. No matter how much homemade baking powder you made, if the recipe calls for 1-1/2 tsp, add exactly 1-1/2 tsp of your mixture.
Cream of tartar is used to increase the acidity of a mixture. So, you can't switch baking soda for baking powder. You can switch baking powder for baking soda, just expect the flavor to change a little.

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Substituting Baking Powder and Baking Soda originally appeared on About.com Chemistry on Tuesday, November 17th, 2009 at 15:36:38.

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