Lawrencium Symbol: Lr
Atomic Number: 103
Atomic Mass: (262.0) amu (atomic mass unit)
Melting point: 1627°C (1900 K or 2961°F)
Boiling Point: Unknown
Number of Protons: 103
Number of Electrons: 103
Number of Neutrons: 159
This element, which was first detected by Albert Ghiorso and his team in 1961 at the Berkley Campus of the University of California, is one of the Rare Earth Elements. Further work in Dubna, Russia identified lawrencium as part of the actinide series of these elements. The Rare Earth Elements are made up of two series of elements, the Lanthanide and Actinide Series with sixteen elements in each. In 1992 the Berkley team and the Dubna team were officially named as the co-discovers of lawrencium by a meeting of the International Union of Pure and Applied Chemistry (IUPAC).
Lawrencium is the last element within the actinide series, so it has the greatest mass of all the Rare Earth elements.. It was named lawrencium after Ernest O. Lawrence the man who invented the cyclotron. The original symbol assigned to the element was Lw but this was changed in 1963 to Lr. It has also been known as eka-lutetium. The name lawrencium along with its symbol (Lr) was ratified by the IUPAC in 1997 at a meeting in Geneva..
There are twelve known isotopes of lawrencium with the longest half life known at present belonging to Lawrencium-262 at 216 minutes; this is also the heaviest isotope to be discovered to date. The lightest isotope currently recognized is Lawrencium-252, which along with Lawrencium-253 are the most recent discoveries being detected in 2001.
Other than that it forms a trivalent ion, lawrencium trichloride (LrCl3) has been synthesized, very little else is known about this element. To date we do not know its crystal structure, color or density but studies of similar elements suggest it should be silvery white or grey and is metallic. At present even its' bulk properties such as boiling and melting points are unknown.
It is a man made element with no natural source on earth. Lawrencium has no known industrial uses at present. If large quantities of this element could be synthesized it would without doubt present a radiation hazard. There are thirty two rare earth elements which are to be found in the lanthanide and actinide series. One element of the lanthanide series and most of the elements in the actinide series are called trans-uranic elements, which means they are synthetic or man-made. All of the rare earth metals are to be found in group 3 of the periodic table, and within the 6th and 7th periods of the table.