Lawrencium is a synthetic chemical element with chemical symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series.
Three reasons Lawrencium stands out
- 1
Named after Nobel laureate for invention of the cyclotron.
- 2
It is the last member of the actinide series and the heaviest element in that group.
- 3
Its chemical properties have challenged theoretical predictions about how heavy elements should behave.
Where the actinides end—depending on the table
Lawrencium is traditionally placed at the end of the actinide row and named for cyclotron inventor Ernest Lawrence. Measurements of its outer electron challenge a simple extrapolation from lighter elements. That makes lawrencium central to debates over exactly where the next transition series begins.