About.com Chemistry

Fun Friday Fire Project - Homemade Firecrackers

Fri, 03 Jul 2009 12:41:37 +0000

Of course! You need to get primed for the big fireworks displays tomorrow, so get started with firecrackers. Now... the thing about this project is, the more gunpowder you use, the bigger bang you will get. Do have fun, but don't go overboard. If you're a diehard do-it-yourselfer, you can make your own gunpowder. Alternatively, you can collect the powder from toy gun caps. I've designated the remainder of the day "4th of July Eve" so start celebrating!

On This Day in Science History - July 3

Fri, 03 Jul 2009 00:05:38 +0000

July 3, 1969 was supposed to be the day the Soviets launched their new N1 rocket. The N1 was their largest rocket design and their answer to the United States' Saturn V rocket. It was just under 350 feet tall. 30 engines in the first stage gave a thrust of almost 10 million pounds and could lift 95 tons of cargo. At least, that was the plan.

Shortly after liftoff a loose bolt fell into the fuel pump and immediately destroyed the pump. 29 of the 30 engines automatically shut down, stalling the rocket. 23 seconds later, the 1,780 tons of liquid oxygen and 680 tons of kerosene fuel exploded, destroying the rocket and the launchpad. This spectacular explosion was the largest rocket explosion to date.

The N1 design never successfully launched and crippled the Soviet efforts to place a man on the moon. Find out what else occurred on this day in science history.

Dr. Anne Helmenstine on NPR's Science Friday on July 3rd

Thu, 02 Jul 2009 18:27:45 +0000

Annette Heist of NPR asked me if I'd join her for Science Friday on July 3rd to talk about science projects for kids, especially 4th of July science projects. It sounds like fun! If you'd like to listen, tune in to NPR's (National Public Radio) Science Friday around 2:15 pm EST / 1:15 CST.

On This Day in Science History - July 2

Thu, 02 Jul 2009 00:05:54 +0000

July 2^nd is the birthday of Hans Bethe. Hans Bethe was a German-American physicist who was awarded the 1967 Nobel Prize in Physics for describing how stars create their energy. He was in a good place to work out ideas in atomic and nuclear physics when he worked in the theoretical division of the Manhattan Project to build America's atomic bomb. He was part of the team that calculated the critical mass necessary for a chain reaction and later worked on the implosion method to start that chain reaction.

After the war, President Truman announced the hydrogen bomb project and Bethe joined the project but hoped it would prove an impossible task. His personal feelings against atomic and thermonuclear weapons showed when he joined Einstein's Emergency Committee of Atomic Scientists against nuclear testing and the arms race. He also played a role in the eventual ban on atmospheric testing and the SALT I Anti-Ballistic Missile Treaty.

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

Wordless Wednesday - Easy Smoke Bomb

Wed, 01 Jul 2009 06:21:49 +0000

You only need two non-toxic ingredients to make smoke bombs for the 4th of July. I've got a video tutorial for you or you can use the written step-by-step smoke bomb tutorial. Have fun!

On This Day in Science History - July 1

Wed, 01 Jul 2009 00:05:57 +0000

July 1^st marks the passing of the man who discovered the process to vulcanize rubber. Charles Goodyear spent several years trying to find a method to convert rubber into a substance that would not turn brittle in the cold or turn to goo in the heat. His early attempts found rubber that would rot after time or still turn sticky in heat. He ultimately found the answer by accident. He spilled a mixture of rubber mixed with sulfur on a hot stove and cured the rubber into a solid mass.

After he patented his process, he started a small company to find uses for his rubber. Unfortunately, he spent most of his efforts on defending his patents and in lawsuits and his business failed. The Goodyear Tire and Rubber Company had nothing to do with Charles Goodyear and was formed 38 years after his death.

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

Where to Buy Saltpeter or Potassium Nitrate

Tue, 30 Jun 2009 17:26:27 +0000

You used to be able to buy potassium nitrate as saltpeter in many garden supply stores. I'm not exactly certain why that has changed, but you can still purchase potassium nitrate, which is used to make smoke bombs and certain other fireworks, as 'stump remover'. In the United States, you can find it at Lowes or Home Depot, among other places. Look for it in those stores near the insecticides.

On This Day in Science History - June 30

Tue, 30 Jun 2009 00:05:04 +0000

June 30^th marks the passing of the man who answered the question: "Why is the sky blue?"

John William Strutt, or Lord Rayleigh determined that the gas molecules in the air scatter the sunlight as it passes through the atmosphere. This scattering effect is called Rayleigh scattering in his honor. The light we see depends on the angle between the light source and you. When the sun is low on the horizon at sunrise or sunset, the longer wavelengths of light are scattered more and you see reds and oranges. As the sun rises higher into the sky, the wavelength that is scattered is shorter and we see blue.

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

10th Grade Science Fair Projects

Mon, 29 Jun 2009 16:09:22 +0000

Some people think it gets easier to come up with science fair project ideas as you get older, but when you're in high school you have a lot on your mind, plus the expectations for a quality science fair project are higher. I asked my oldest son, who will be in 10th grade this year, what he thought would be good ideas for science fair projects. He drew a blank and I'm guessing most 10th grade students are in the same boat. Not to fear! I've drawn up a list of 10th grade science fair project ideas. If you have ideas for other science projects appropriate for the high school level, please feel free to post a reply.

On This Day in Science History - June 29

Mon, 29 Jun 2009 00:05:19 +0000

June 28^th marks the passing of the man who introduced us to plastic. Alexander Parkes was a British chemist and metallurgist who created the first thermoplastic which he called Parkesine. Parkesine was a nitrocellulose compound that aroused great public interest when it was introduced at the 1862 Grand International Expedition. Parkes established a business to exploit its popularity, but ultimately failed within two years for two reasons. The first, Parkes would reduce quality to make his products less expensive. The second, and probably more important, Parkesine is highly flammable. Customers did not like cheap plastic products that burned really easily.

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