January 5^th marks the passing of Harold Urey. Urey was an American chemist who was awarded the 1934 Nobel Prize in Chemistry for his discovery of deuterium.

Deuterium is an isotope of hydrogen. The most common form of hydrogen has one proton and one neutron, but deuterium has an extra neutron in its nucleus. This isotope has the same chemical properties as hydrogen and can combine with oxygen to create water. Deuterium water is also known as 'heavy water'. Heavy water is used in many applications such as nuclear magnetic resonance, neutron moderation in nuclear power plants and organic chemistry.

Urey discovered deuterium by investigations of heavy water in 1931 and was important in the understanding of the concepts of isotopes. Find out what else occurred on this day in science history.

It isn't scientific to assume scientists are smart. To determine whether scientists are smart, a scientist would obtain data and test a hypothesis to verify that the average IQ of a scientist is statistically higher than that of the norm. Science can't take the obvious for granted. However, there are studies that yield totally unsurprising results. You already suspected this, but now scientists have verified:

• Eating lots of processed meat is bad for you.

• A lot of advertisements for high sugar and high fat food are shown during kids tv programming.

• Kids are affected when a parent is depressed.

Interested in learning more? FoxNews has a list of the Most Obvious Scientific Discoveries of 2009.

January 4^th marks the passing of Erwin Schrödinger. Schrödinger was an Austrian physicist who was one of the founders of quantum mechanics. He described the quantum state of a particle by its wavefunction. His equation is one of the basic equation of quantum mechanics.

He is also famous for a thought experiment that has become known as Schrödinger's cat. The Heisenberg principle states the position and the velocity of a particle cannot be exactly measured with perfect accuracy. Similarly, quantum mechanics shows probabilities of position and velocity and all values are possible, some values being more possible than others, and does not exist until the observer measures it. Schrödinger tried to explain that this did not apply to larger things. He proposed a system where a cat was locked into a closed container with a small amount of radioactive material, a geiger tube, and a device that kills the cat if radiation is detected by the geiger counter. It only takes one disintegrating atom to kill the cat, but whether or not the atom decays is left to chance and probability. According to the rules of quantum mechanics, the cat is neither dead nor alive until someone opens the box to check. Schrödinger argued that this was a silly way to explain quantum mechanics to situations where it doesn't apply.

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

I took a look back over all of the chemistry projects written for About.com's Chemistry website and made up a list of the most popular projects of the decade. This is the same list as 'best chemistry projects of all time' (which sounds way cooler), since I started writing for About.com in 2001.

Have you tried these chemistry projects? Do you have any personal favorites I left off the list?