Lawrencium

Lawrencium is a chemical element that is synthetic as well as radioactive, and is only used in laboratories for research. It has the symbol Lr with an atomic number of 103, and an atomic mass of 262.0 amu's. . It is the last element in the actinide series. Lawrencium is chemically similar to the other actinides and can be found in the periodic table 7 d-block.

Much about lawrencium is unknown. There is no known melting point, boiling point, crystal structure, density, or color. Lawrencium has only been produced in very small amounts. If large amounts of lawrencium were actually produced, this element would pose a radiation hazard. Lawrencium does form isotopes, however these isotopes are synthetic and they all have a very short half-life.

Properties
The properties of lawrencium are currently unknown since not many of these particles have been produced, and the atoms decay at a very rapid rate. Because of this, scientists have a difficult time studying this element. However, lawrencium has been assumed to be solid since it is classified as a transition metal. Lawrencium-262 is lawrencium's most stable isotope. It has a half-life that lasts 3.6 hours. Lawrencium decays easily, and does so through electron capture or spontaneous fission. Nobelium-256 is produced through this decay. There are no stable isotopes in lawrencium, and its ionization energy is unknown. Lawrencium has an oxidation state of +3. Thomas Jefferson National Accelerator Facility - Office of Science Education. Web. Accessed November 17, 2011.

Occurrences
The element lawrencium is man made, so it can only be found in nuclear physics and nuclear chemistry laboratories. Lawrencium was first produced in 1961 at the Lawrence Berkeley National Laboratory of the University of California. The appearance is also unknown but it has been assumed to have a metallic and silvery white or gray in appearance.

Uses
Since only tiny amounts of lawrencium have ever been produced, there are currently no uses for it outside of basic scientific research.

History
The element name lawrencium is a reference to the nuclear-physicist Ernest O. Lawrence, of the University of California. Lawrence is also known as the inventor of the particle accelerator and atom smasher known as the cyclotron. Lawrencium was first discovered on February 14, 1961 by four American scientists, Albert Ghiorso, Torbjørn Sikkeland, Almon E. Larsh and Robert M. Latimer. These scientists worked at the Lawrence Radiation Laboratory in Berkeley, California.

Originally the symbol Lw was used to stand for this element. This symbol later changed and was assigned the letters Lr in 1997. This element was first produced by placing three micrograms of californium with boron-10 and boron-11 which were bombarded in the target chamber of a device called a heavy ion linear accelerator. It can also be produced by bombarding americium with oxygen. The team obtained several lawrencium isotopes. Unfortunately, the atoms decayed very quickly (in only three minutes). When lawrencium decays it turns into nobelium.

Studies using Lawrencium
A study was completed in 1969 by the nuclear-physics team at the Flerov Laboratory of Nuclear Reactions (FLNR) in the Soviet Union. They produced lawrencium nuclei by using the nuclear reaction 243Am+18O. They then exposed it to a stream of chlorine gas. A product was formed that was determined to be 256LrC13. The scientists concluded from this study that lawrencium is indeed a typical actinide element. There was also a study in 1970 by the nuclear-physics team at the Lawrence Berkeley National Laboratory. They also produced Lawrencium nuclei by using the nuclear reaction 249Cf+11B. This study showed that Lawrencium forms a trivalent ion that is similar to those found in other actinide elements.

Scientists Who Discovered Lawrencium
Albert Ghiorso was a nuclear scientist from America. He was the co-discoverer of 12 different chemical elements that are currently on the periodic table. Some of these elements were einsteinium(99), fermium(100), nobelium(102), rutherfordium(104), dubnium(105), seaborgium(106), and of course lawrencium(103). Ghiorso was in charge of the Berkeley Heavy Ion Linear Accelerator which played a large part in the discovery of lawrencium.

Torbjørn Sikkeland was the co-discoverer of nobelium and lawrencium. He received a scholarship from Norges Teknisk-Naturvitenskapelige Forskningsråd so that he could perform research at the Lawrence Berkeley Laboratory, University of California, Berkeley and lived there from 1957 to 1969. Later, he became a physics professor at the Norwegian Institute of Technology in Trondheim Norway. He has done many other studies in radiation biophysics and nuclear physics.

Almon E Larsh, an American electrical engineer, attended the California Institute of Technology. He worked in the radiation laboratory at the Lawrence Berkeley National Laboratory. His greatest accomplishment was his co-discovery of the element lawrencium.

Robert M Latimer was an American nuclear chemist. He was the head of the nuclear chemistry group at the Lawrence Berkeley Lab. He was in charge of the production of nuclear elements. He worked with Albert Gorsio to discover the element lawrencium. After a long career at the lab, Latimer worked in the Risk Management department at the Livermore National Laboratory in Livermore, California.

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