Lawrencium (Lr)
Isotopes of Lawrencium
| Isotope | Atomic Mass | Half-life | Mode of Decay | Nuclear Spin | Nuclear Magnetic Moment |
| Lr-255 | 255.0967 | 22 seconds | α to Md-251; EC to No-255 |
No data available | No data available |
| Lr-256 | 256.0988 | 28 seconds | α to Md-252; EC to No-256; SF |
No data available | No data available |
| Lr-257 | 257.0996 | 0.65 seconds | α to Md-253; SF | 7/2 | No data available |
| Lr-258 | 258.1019 | 3.90 seconds | α to Md-254; EC to No-258; SF |
No data available | No data available |
| Lr-259 | 259.1030 | 6.10 seconds | α to Md-255; EC to No-259; SF |
No data available | No data available |
| Lr-260 | 260.105320 | 3 minutes | α to Md-256; EC to No-260; SF |
No data available | No data available |
| Lr-261 | 261.1069 | 40 minutes | SF | No data available | No data available |
| Lr-262 | 262.1097 | 3.60 hours | EC to No-262; SF | No data available | No data available |
Lawrencium is a synthetic rare earth metal which does not occur in the environment. It was discovered in 1961 by Albert Ghiorso, Torbjørn Sikkeland, Almon Larsh and Robert M. Latimer at the University of California - Berkeley, USA. The origin of the name is that of Ernest O. Lawrence, inventor of the cyclotron.
Chemistry experiments have confirmed that lawrencium behaves as the heavier homologue to lutetium and is chemically similar to other actinides.
Properties of Lawrencium
| Name | Lawrencium |
| Symbol | Lr |
| Atomic number | 103 |
| Atomic weight | [262] |
| Standard state | Presumably a solid at 298 °K |
| CAS Registry ID | 22537-19-5 |
| Group in periodic table | 3 |
| Group name | None |
| Period in periodic table | 7 |
| Block in periodic table | d-block |
| Color | Unknown, but probably metallic and silvery white or grey in appearance |
| Classification | Metallic |
| Melting point | About 1900 °K [or 1627 °C or 2961 °F] (predicted) |
| Boiling point | No data available |
| Electron configuration | [Rn]7s25f147p1 |
