Portal:Chemistry

In nature, uranium atoms exist as uranium-238 (99.275%), uranium-235 (0.72%), and a very small amount of uranium-234 (0.0058%). Uranium decays slowly by emitting an alpha particle. The half-life of uranium-238 is about 4.5 billion years and that of uranium-235 is 700 million years, making them useful in dating the age of the Earth (see uranium–thorium dating, uranium–lead dating and uranium–uranium dating). Along with thorium and plutonium, it is one of the three fissile elements, meaning it can easily break apart to become lighter elements. This property of uranium-235 and to a lesser degree uranium-233 generates the heat needed to run nuclear reactors and provides the explosive material for nuclear weapons. Both uses rely on the ability of uranium to produce a sustained nuclear chain reaction. Depleted uranium (uranium-238) is used in kinetic energy penetrators and armor plating.

Research by Enrico Fermi and others starting in 1934 led to its use as a fuel in the nuclear power industry and in the first nuclear weapon used in war (see Little Boy and atomic bombings of Hiroshima and Nagasaki). An ensuing arms race during the Cold War between the United States and the Soviet Union produced tens of thousands of nuclear weapons that used enriched uranium and uranium-derived plutonium. The security of those weapons and their fissile material following the dissolution of the Soviet Union in 1991 along with the legacy of nuclear testing and nuclear accidents is a concern for public health and safety.

Fields of Chemistry

• Analytical chemistry: Chromatography, Spectroscopy
• Biochemistry: Molecular biology
• Crystal Chemistry
• Environmental chemistry: Geochemistry
• Inorganic chemistry: Inorganic reactions
• Materials science: Nanotechnology, Glass, Ceramics
• Medicinal chemistry
• Metallurgy
• Nuclear chemistry
• Organic chemistry: Functional groups, Organic compounds, Organic reactions
• Organometallic chemistry
• Pharmacy
• Physical chemistry: Electrochemistry, Quantum chemistry
• Polymer chemistry
• Supramolecular chemistry
• Theoretical chemistry: Computational chemistry

Many chemists have an interest in the history of chemistry. Those with philosophical interests will be interested that the philosophy of chemistry has quite recently developed along a path somewhat different from the general philosophy of science.

Other articles that might interest you are:

• Superseded chemistry theories
• Alchemy
• Scientific method
• The central science

There is a Wikipedia Project on the History of Science.

Wikipedia:WikiProject Chemicals/Data is a collection of links and references that are useful for chemistry-related works. This includes free online chemical databases, publications, patents, computer programs, and various tools.

unit-conversion.info A good place to figure out what equals what.

General Chemistry Online Clear text and comprehensive coverage of general chemistry topics by Fred Senese, Dept. of Chemistry Frostburg State University

General Chemistry Demonstration at Purdue Video clips (and descriptions) of lecture demonstrations.

Chemistry Webercises Directory A large listing of chemistry resources maintained by Steven Murov, Emeritus Chemistry Professor Modesto Junior College.

MathMol MathMol (Mathematics and Molecules) is a good starting point for those interested in the field of molecular modeling.

ABC-Chemistry A directory of free full-text journals in chemistry, biochemistry and related subjects.

The Element Song A goofy little song about all of the elements.