noun Chemistry, Physics.
- a transuranic element in the actinium series. Symbol: No; atomic number: 102.
- a transuranic element produced artificially from curium. Symbol: No; atomic no: 102; half-life of most stable isotope, 255 No: 180 seconds (approx.); valency: 2 or 3
n.1957, from Nobel + -ium. n. Symbol No
- A radioactive synthetic element in the actinide series; its longest-lived isotope is No 259 with a half-life of 58 minutes. Atomic number 102.
- A synthetic, radioactive metallic element in the actinide series that is produced by bombarding curium with carbon ions. Its longest-lived isotope is No 255 with a half-life of 3.1 minutes. Atomic number 102. See Periodic Table.