2. URANIUM By: Munish R. Adhikari

3. Discovery Of Uranium Uranium was discovered by Martin Heinrich Klaproth in 1789. Martin Heinrich Klaproth was analysing a mineral called pitchblende and discovered a black powder in it. The black powder was incorrectly called uranium, however, it was an oxide of uranium. French Scientist, Eugene Peligot isolated the pure metallic element in 1841. French Physicist Antoine Becquerel discovered the radioactive properties of uranium. Marie and Pierre Curie, the French/Polish scientists, explored radioactivity and found that it was associated with atoms in 1898, leading to the discovery of polonium and radium from the pitchblende.

4. Characteristics of Uranium Uranium is a radioactive element. Uranium occurs naturally in varying but small amounts in soil, rocks, water, plants, animals, and all human beings. It is the heaviest naturally occurring element, with an atomic number of 92. In its pure form, uranium is a silver-colored heavy metal that is nearly twice as dense as lead. In nature, uranium exist as several isotopes. Uranium-238 (meaning 238 protons and neutrons in the nucleus), uranium-235 and uranium-234. Since Uranium is radioactive, the nuclei spontaneously disintegrates/decays.

5. Characteristics of Uranium Continued Uranium, the naturally occurring metal and its isotopes have a half life. Half life is the time it takes for half of the radioactive substance to decay. Uranium-234 has a half life of 248,000 years Uranium-235 has a half life of 700 Million years. Uranium-238 has a half life of 4.5 billion years. These are the key uranium isotopes (234, 235 and 238).

6. Uses of Uranium, Present and Past Uranium was primarily as a colorant in ceramic glazes to produce colors ranging from orange-red to lemon yellow. It was used for tinting in early photography. It is currently used as a fuel in nuclear power reactors to generate electricity. It is used in weapons applications. It is used in small nuclear reactors to produce isotopes for medical and industrial purposes around the world.

7. Source of the Element Uranium is found in numerous minerals, such as pitchblende, uraninite, carnotite, autunite, uranophane and tobernite. Uranium is also found in phosphate rock, lignite, monazite sands, and can be recovered commercially from these sources. Uranium is one of the most unstable elements known to man. Uranium is so active that it is nearly impossible to purify. Uranium clings tightly to any impurities

8. Final Notes on Uranium Uranium is the most dense naturally occurring element known to man. Uranium can be used for weapons, energy or medicine. Uranium is radioactive. Homer handles Uranium.

9. Bibliography “About Uranium: Discovery of Uranium” http://www.uraniumsa.org/about/discovery.htm January 12, 2006. http://www.uraniumsa.org/about/discovery.htm “What is Uranium?” Depleted UF6. http://web.ead.anl.gov/uranium/guide/ucompound/whatisu/ index.cfm January 12, 2006. http://web.ead.anl.gov/uranium/guide/ucompound/whatisu/ index.cfm “Characteristics of Uranium and Its Compounds” US Department of Energy Office of Environmental Management” Fall 2001. http://web.ead.anl.gov/uranium/pdf/UraniumCharacteristic sFS.PDF January 12, 2006. http://web.ead.anl.gov/uranium/pdf/UraniumCharacteristic sFS.PDF “Uranium” 5 Fantastic Elements. http://library.thinkquest.org/J002959F/uranium.htm January 12, 2006. http://library.thinkquest.org/J002959F/uranium.htm