STEM Chem Nuclear Chemistry

Published by admin on

the spontaneous emission of rays or particles from certain elements
nuclear radiation
the rays and particles emitted from a radioactive source
unstable isotopes
unlike chemical reactions, nuclear reactions are not affected by changes in
temperature, pressure, or the presence of catalysts
Nuclear reactions of a given isotope cannot be
slowed down, sped up, or stopped
three types of nuclear radiation are
alpha radiation, beta radiation, and gamma radiation
alpha particle
helium nuclei (two protons, two neutrons, and has a double positive charge)
beta particle
an electron resulting from the breaking apart of a neutron in an atom
gamma ray
a high-energy photon emitted by a radioisotope (no mass, no charge)
nuclear force
an attractive force that acts between all nuclear particles that are extremely close together (such as proton and neutron in the nucleus)
band of stability
the region of the graph in which these points are located ( on graph of number of neutrons vs. protons for all known stable nuclei)
The type of decay that occurs is determined by the
neutron-to-proton ratio in a radioisotope
a particle with the mass of an electron but a positive charge
After each half-life, half of
the original radioactive atoms have decayed into atoms of a new element
the conversion of an atom of one element into an atom of another element
transmutation can occur by
radioactive decay, or when particles bombard the nucleus of an atom
transuranium elements
elements with atomic numbers above 92, the atomic number of uranium
when the nuclei of certain isotopes are bombarded with neutrons, the nuclei split into smaller fragments
in a chain reaction, some of the emitted neutrons
react with other fissionable atoms, which emit neutrons that react with still more fissionable atoms
neutron moderation
a process that slows down neutrons so the reactor fuel can capture them to continue the chain reaction
neutron absorption
a process that decreases the number of slow-moving neutrons
occurs when nuclei combine to produce a nucleus of greater mass
fusion reacts, in which small nuclei
combine, release much more energy than fission reacts, in which large nuclei split apart and form smaller nuclei
Antoine Henri Becquerel
made an accidental discovery that the uranium atoms caused the film to fog
Marie and Pierre Curie
they were able to show that rays emitted by uranium atoms caused the film to fog
if the product of a nuclear reaction is unstable,
it will decay too
the process (of decay) continues until
unstable isotopes of one element are changed, or transformed, into stable isotopes of a different atom (not radioactive)
balanced nuclear equation
the sum of mass numbers on the right must equal sum on left
an atom is unstable (radioactive) if
it doesn’t have the right ratio of protons to neutrons
Categories: Nuclear Chemistry