Question:
i have read somewhere that tellurium is the lightest
element that can undergo alpha decay. But i have read that
beryllium-8 can undergo alpha decay. Which is true?
Replies:
Lee,
When an unstable isotope undergoes alpha decay the nucleus gives
up two neutrons and two protons. This type of decay will define
the atom with the lowest atomic number that can undergo alpha
decay.
You are correct: several of the lower mass isotopes of tellurium do
undergo alpha decay; beryllium-8 also undergoes alpha decay.
Yet, beryllium-6 undergoes alpha decay, lithium-5 undergoes alpha
decay, and helium-5 undergoes alpha decay. Hydrogen has only one
proton, therefore none of the isotopes of hydrogen can undergo alpha
decay. It looks like helium-5 is the winner of your contest.
Take a look at the Nuclear Wallet Cards from the National Nuclear
Data Center of the Brookhaven National Laboratories at
http://www.nndc.bnl.gov/wallet/nwccurrent.html.
Les
Leslie Kanat, Ph.D.
Professor of Geology
Department of Environmental Sciences
Johnson State College
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