Chart of the Nuclides: plot of P vs. N. Show plot of stable nuclei: the belt
of stability. If the N/P ratio is too high, it can be remedied by ?- decay
or by neutron emission. Beta emission is the more common of the two. If the
N/P ratio is too low, that condition can be remedied by ?+ emission, or by
K-capture (an inner-shell electron is captured by the nucleus.) If the nuclide
is beyond the belt of stability (if 84 or more protons) it must be rectified
by splitting off larger chunks (usually alpha particles), perhaps in several
steps. E.G.
Also, radioactive displacement law on periodic table.
Another example:
spontaneous and induced
first particle other than proton, electron, and neutron
antimatter
describe first discovery of radioactivity, and cloud/bubble chambers
The first manmade element was technetium (43), created in 1939 and named from
the Greek word ¬_???__, meaning 'artificial'. This continued the tradition
of elements' creators having the honor of naming their creations, just as the
discoverers of the natural elements in the 1800s did.
In 1930 Wolfgang Pauli postulated the existence of the neutrino to account for
apparently missing energy and momentum when a nucleus beta-decays. 1934: Enrico
Fermi constructs working model of beta decay, paving the way to atomic energy
and weapons.
Neutrino first observed by Reines and Cowan in 1953, by using a 10 ft3 scintillator,
via the weak interaction and the neutron conversion .
Using a geiger counter, and how it works.
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Activities & Practice
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