'unnilseptium' definitions:
Definition of 'unnilseptium'
From: Elements
- Symbol:
- Atomic number: 107
- Atomic weight: (262)
- Radioactive transition metal. Half-life of approximately 1/500 s. Discovered by the Joint Institute for Nuclear Research at Dubna (U.S.S.R.) in 1976. Confirmed by West German physicists at the Heavy Ion Research Laboratory at Darmstadt.