Lawrencium is a synthetic element and is highly radioactive and unstable element. It is the last member of the actinide series of the periodic table.
History and Discovery
Lawrencium was synthesized independently by team of scientist working at the Joint Institute for Nuclear Research (JINR), Dubna and American Lawrence Berkeley Laboratory (LBL). In 1961, a team of physicist working at Berkeley, Almon Larsh, Torbjorn Sikkeland, Albert Ghiorso and Robert Latimer synthesized an atom of lawrencium by bombarding californium target with boron nuclie. Later, in 1965, a tea of scientist working at Dubna successfully reported the production of element 103. he JINR team bombarded a americium-243 target with oxygen-18 ions and produced an two atoms of element 103, lawrencium-256 and lawrencium-257. International Union of Pure and Applied Chemistry (IUPAC) credited both teams for the discovery of lawrencium in 1992. The name lawrencium was officially announced in 1997 and was given after Ernest Lawrence, who discovered the device used for the discovery of various radioactive elements, cyclotron. The symbol of lawrencium is Lr [1].
Lawrencium
| Periodic Table Classification | Group n/a Period 7 |
|---|---|
| State at 20C | Solid (predicted) |
| Color | Silvery (predicted) |
| Electron Configuration | [Rn] 5f14 7s2 7p1 |
| Electron Number | 103 |
| Proton Number | 103 |
| Electron Shell | 2, 8, 18, 32, 32, 8, 3 |
| Density | ~15.6–16.6 g.cm-3 at 20°C (predicted) |
| Atomic number | 103 |
| Atomic Mass | 262.00 g.mol -1 |
| Electronegativity according to Pauling | 1.30 (predicted) |
Occurrence
Lawrencium is an artificial element and does not exist in nature and only is produced in a laboratory.
Physical Characteristics
Lawrencium is predicted to be a solid under normal conditions. The unstable nature lawrencium makes it difficult to carry out a statistically significant analysis of its physical and chemical characteristics. Lawrencium is the eleventh transuranic element to be discovered. It is the last member of the actinide series. The expected density of lawrencium is around 16.6 g/cm3 and is considered a heavy metal. Lawrencium is expected to be a volatile element and resembles lead in its volatility. The melting point of lawrencium is predicted to be around 1627°C [2].
Chemical Characteristics
The chemical characteristics of lawrencium have not been well studied yet. Lawrencium is predicted to resemble the transition metals of the 7th period of the periodic table. It is predicted to resemble lutetium in its chemical and physical properties. The most common oxidation state of lawrencium has been predicted to be +3. Lawrencium is predicted to be reactive towards oxygen and air. It will also react with hot water and acids [3].
Significance and Uses
- Lawrencium is used for research purposes.
Health Effects
Lawrencium is a radioactive element and requires special precautions with handling and storage.
Isotopes of Lawrencium
There are twelve isotopes of lawrencium, with mass number ranging from 252-262, and 266 [4]. They are unstable and unnatural [3]. The most stable isotope is lawrencium-266 that has a half-life of eleven hours. Lawrenium-260 has a half-life of around three minutes and is widely used in laboratory experiments as it is easily produced. Most of the isotope of lawrencium undergo decay through emission of alpha particles.
REFERENCES
[1]. Greenwood, Norman N. (1997). “Recent developments concerning the discovery of elements 101–111” (PDF). Pure Appl. Chem. 69 (1): 179–184. doi:10.1351/pac199769010179
[2]. Lide, D. R., ed. (2003). CRC Handbook of Chemistry and Physics (84th ed.). Boca Raton, FL: CRC Press.
[3]. John Emsley (2011). Nature’s Building Blocks: An A-Z Guide to the Elements. Oxford University Press. pp. 278–9. ISBN 978-0-19-960563-7.
[4]. Silva, p. 1642