Definition of "nobelium" [nobelium]

• A radioactive transuranic element in the actinide series with atomic number 102, artificially produced in trace amounts. Its most long-lived isotopes are No 254 with a half-life of 55 seconds, No 253 with a half-life of 1.7 minutes, No 255 with a half-life of 3.1 minutes, and No 259 with a half-life of 58 minutes. See Table at element. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""Precisely measuring the mass of nobelium with our … device was a successful first step," said Block."
• "Now the international team of scientists headed by Michael Block reports it was able to trap atoms of the element 102, nobelium, in an ion trap."
• "Inside the Shiptrap apparatus, the nobelium was first decelerated in a gas-filled cell, then the slow ions were trapped in a so-called Penning trap."