TOPIC 11 - Radiation Friend or Foe? (Nuclear Chemistry) Flashcards
what nuclei were created in the moments following the big bang
hydrogen and helium
the nucleus of one element can fuse with one of another element when exposed to _________ and ___________ creating __________
high heat and pressure creating the nucleus of a heavier element
when nuclear fusion happens what is emitted
huge amounts of energy are released in the form of heat, light and cosmic radiation/rays.
the higher the temperature and pressure the _________ the ________.
heavier the element.
the energy produced by supernovae produces nuclei heavier than
iron
some isotopes are naturally unstable and changes in the nucleus allow
the atom to become more stable
unstable atoms are described as
radioisotopes
radioisotopes are described as
unstable atoms
types of radiation
alpha, beta, gamma
mass of alpha particles are
a helium nucleus (2protons, 2neutrons) 4amu
alpha particles are stopped by
a few cm of air or a sheet of paper
mass of beta particles are
a fast moving electron (e-1) 0amu
beta particles are stopped by
a few cm/sheet of aluminium
gamma particles are stopped by
several cm of lead or a few metres of concrete
mass of gamma particles are
high energy EM wave 0 amu
nuclide notation of alpha
⁴₂He
nuclide notation of beta
⁰₋₁ e⁻
when a radioisotope undergoes alpha decay it (numbers)
loses 4 from atomic and loses 2 from charge/atomic
when a radioisotope undergoes beta decay it (numbers)
gains 1 to charge/atomic
radiation is measured using a
GM tube
the time for each half-life to undergo is
the same
you cannot measure the age of fossil fuels using carbon dating as
they are too old and the carbon would have all decayed by now
the half-life of the only radioactive naturally occurring isotope of carbon (C14) is
5730 years
carbon dating takes the concentration of
C14 in decaying living matter
carbon dating is used to
work out how old something is by working out he quantity of C14 that has decayed
uses of radiation
alpha - smoke detectors
beta - thickness of paper
gamma - tracking movement of water / detecting cracks
uses of radiation in medicine
technitum-99 is used as a tracer to detect infection or other problems
cobalt-60 kills cancer cells in tumours
uses of radiation in industry
uranium-235 is used to generate power using fission chain reactions in nuclear power plants
what affects half-life?
nothing
does changing mass affect half-life?
no
The activity of an atom depends on its
Proton: neutron ratio
