Dubnium
- The Soviets bombarded americium-243
- with neon-22 ions and looked for
- a new alpha emission energy
- for an isotope of element 105,
- but they figured it was obscured
- by emissions from the decay of uranium
- synthesized from lead impurities
- in the americium target.
- So they began to look
- for a new half-life and found one,
- around two seconds,
- which they said was from an isotope of 105.
- *
- The Americans bombarded californium-249
- with nitrogen-15 ions and found an alpha emission
- that overlapped with the noise
- that obscured results for the Soviets.
- *
- The Soviets removed their lead impurities
- ran the experiment again,
- and found the same alpha emission
- plus decay chains involving lawrencium,
- which meant that the Soviets
- had originally found
- either dubnium-260 or dubnium-261,
- although its half-life best matched dubnium-260.
Atomic number 105
- The longest lived isotope, dubnium-268,
- decays by half in twenty-nine hours,
- leaving various isotopes by spontaneous fission
- and rutherfordium-268 by electron capture.
- The shortest lived isotope, dubnium-259,
- decays by half in half a second,
- leaving, by alpha emission, lawrencium-255,
- which, in its turn, decays.
Pattern
- All the heavy elements decay.
- If they had no other interest,
- all they would be would be
- an equal weight of lead.
- But they sparkle, they scintillate,
- they drop hints about old connections.
- Eventually, you would think,
- a pattern would emerge that might
- solve the problems of the world.
If it weren’t for the unknown, our knowlege would be less interesting.
See also in The book of science:
Readings on wikipedia:
Other readings: