Term | Definition |
alpha particle | a positively
charged atomic particle that is much
more massive than either a beta
particle or gamma radiation and is
relatively slow moving; has same
combination of particles as the
nucleus of a helium atom |
beta particle | a high speed
electron; emitted by a radioactive
nucleus in beta decay |
chain reaction | an ongoing process in
which one fission reaction initiates
the next reaction |
daughter isotope | the stable product
of radioactive decay |
decay curve | a curved line on a graph
that shows the rate at which
radioisotopes decay |
fission | a nuclear reaction in which a
large nucleus breaks apart, producing
two or more smaller nuclei,
subatomic particles, and energy |
fusion | a process in which two low
mass nuclei join together to make a
more massive nucleus |
gamma radiation | rays of highenergy,
short-wavelength radiation
emitted from the nuclei of atoms |
half-life | the time it takes for a living tissue, organ, organism, or ecosystem to eliminate one half of
a substance, in physics, the time
required for half the nuclei in a
sample of a radioactive isotope to
decay, which is constant for any
radioactive isotope |
isotopes | different atoms of a
particular element that have the same
number of protons but a different
numbers of neutrons |
light | one form of radiation that is
visible to humans |
mass number | the total number of
protons and neutrons found in the
nucleus of an atom |
nuclear equation | a set of symbols
that indicates changes in the nuclei
of atoms during a nuclear reaction |
nuclear reaction | the process in which
an atom’s nucleus changes by
gaining or releasing particles or
energy |
parent isotope | the isotope that
undergoes radioactive decay |
radiation | high-energy rays and
particles emitted by radioactive
sources |
radioactive decay | the process in
which the nuclei of radioactive
parent isotopes emit alpha, beta, or
gamma radiation to form decay
products |
radiocarbon dating | determining the
age of an object by measuring the
amount of carbon-14 remaining in it |