About Chemistry

Wordless Wednesday - Colored Fire Pinecones

2009-11-25T06:57:45Z

Toss one or more of these treated pinecones onto your holiday fire for colored flames.

Wordless Wednesday - Colored Fire Pinecones originally appeared on About.com Chemistry on Wednesday, November 25th, 2009 at 06:57:45.

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On This Day in Science History - November 25 - Julius Robert von Mayer

2009-11-25T00:05:41Z

November 25^th is Julius Robert von Mayer's birthday. Mayer was a German physician who had a hobby of studying physics. Most of his work centered around how energy was transferred from one form to another. He was one of the first to recognize that plants converted light into chemical energy, and the process of oxidation was the primary source of energy in living creatures. He also outlined the earliest versions of what would become the first law of thermodynamics by writing "Energy is neither created nor destroyed".

He attempted to publish his ideas as conservation of force, but had several basic errors due to his lack of formal physics training and was largely ignored. James Joule published his work a year later describing the conservation of energy and mechanical equivalent of heat and gained recognition as the 'founder of modern thermodynamics'. This, and the death of two of his children, drove Mayer to the brink of suicide and spent time in mental institutions. After he left the institutions, he began publishing again and was recognized for his earlier work and given an honorary doctorate and personal nobility in Germany.

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

On This Day in Science History - November 25 - Julius Robert von Mayer originally appeared on About.com Chemistry on Wednesday, November 25th, 2009 at 00:05:41.

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Easy Dessicant Container (Dessicator)

2009-11-24T11:48:26Z

Have you ever wondered why so many products come with little packets that say 'Do Not Eat'? The packets contains silica gel beads, which absorb water vapor and keep the product dry, which is an easy way of preventing mold and mildew from taking their toll. Other items would absorb water unevenly (e.g., parts of a wooden musical instrument), causing them to warp. You can use the silica packets or another dessicant to keep special items dry or to keep water from hydrating chemicals. All you need is a hygroscopic (water-absorbing) chemical and a way to seal your container.

Common Dessicant Chemicals

silica gel (the beads in those little packets)
sodium hydroxide (sometimes sold as a solid drain cleaner)
calcium chloride (sold as a solid laundry bleach or a road salt)

Make a Dessicator

This is extremely simple. Just place a small amount of one of the dessicant chemicals into a shallow dish. Enclose an open container of the item or chemical you wish to dehydrate with the container of dessicant. A large plastic bag works well for this purpose, but you could use a jar or any airtight container.

The dessicant will need to be replaced after it has absorbed all of the water that it can hold. Some chemicals will liquefy when this occurs so that you will know they need to be replaced (e.g., sodium hydroxide). Otherwise, you'll just need to switch out the dessicant when it starts to lose its effectiveness.

Easy Dessicant Container (Dessicator) originally appeared on About.com Chemistry on Tuesday, November 24th, 2009 at 11:48:26.

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On This Day in Science History - November 24 - W and Z bosons

2009-11-24T00:05:04Z

November 24^th is Simon van der Meer's birthday. He is a Dutch physicist who, together with Carlo Rubbia, first detected the existence of W and Z particles during a series of experiments at the CERN Super Proton Synchrotron in 1983. Their discovery confirmed the electroweak theory of subatomic particles that unify the electromagnetic force and weak nuclear force. They are also important to the Standard Model of particle physics.

W and Z particles are the carriers of the weak nuclear force, one of the four fundamental forces of physics. The W particles carry a charge of either +1 or -1 and the Z particle carries no charge. They are massive particles, approximately 100 times the mass of a proton, but have a half-life of only 3 x 10^-25 seconds. They are typically present when beta nuclear decay occurs. During β^- decay, one of the down quarks in the neutron becomes an up quark, turning the neutron into a proton and emits a W particle. The W particle quickly decays and produces an electron (beta particle) and an anti-neutrino.

The discovery of W and Z bosons would earn both men the 1984 Nobel Prize in Physics. Find out what else occurred on this day in science history.

On This Day in Science History - November 24 - W and Z bosons originally appeared on About.com Chemistry on Tuesday, November 24th, 2009 at 00:05:04.

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Common Chemicals and Where to Find Them

2009-11-23T09:55:33Z

You don't have to be affiliated with a lab or school to try your hand at chemistry. There are a ton of chemistry projects you can do using common household chemicals. I'm working on a list of common chemicals that you can get or can make from other household chemicals, plus you can add your own suggestions for obtaining relatively pure common chemicals. Chemical availability varies greatly from one country to another, so these lists should make it easier for home chemists to find what they are seeking. Enjoy!

Common Chemicals and Where to Find Them originally appeared on About.com Chemistry on Monday, November 23rd, 2009 at 09:55:33.

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On This Day in Science History - November 23 - Henry Moseley

2009-11-23T00:05:29Z

November 23^rd is Henry Gwyn Jeffreys Moseley's birthday. Moseley was the English physicist who gave meaning to an element's atomic number. Before his work, the atomic number of an element was just its position on the periodic table. Moseley related an element's atomic number to the charge of that element's nucleus. Today, an element is determined by its atomic number or the number of protons in its nucleus.

Unfortunately, World War I interrupted this physicist's career and he enlisted in the Royal Engineers. He was killed during the Battle of Gallipoli in 1915 when he was only 27 years old. Find out what else occurred on this day in science history.

On This Day in Science History - November 23 - Henry Moseley originally appeared on About.com Chemistry on Monday, November 23rd, 2009 at 00:05:29.

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Thanksgiving Chemistry

2009-11-22T08:12:21Z

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

2009-11-22T00:05:33Z

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

2009-11-21T08:53:09Z

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

2009-11-21T00:05:32Z

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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