This topic does not have any feasible, applicable laboratory activities
associated with
it. If, by some chance, your high school owns a Geiger counter (try
the physics
teacher) or cloud chamber and a source of a or b emission, these items
can be used
for demonstrations. A sealed b source can be used to expose Polaroid
TM film. Half life
can be demonstrated by starting out with a known number of candy corn
or other
object and diminishing by half each time. Dismissing a class by coin
toss can simulate
the decay process (probability).
1. Relative energy calculations comparing the output of physical, chemical,
and
nuclear processes (see Appendix). Discuss the abundance
of raw materials
and compare that with the efficiency of energy conversion.
2. Have students understand the effects of a chain reaction. These effects
can
be illustrated by:
a. generating a “picture in the mind” of a room
full of mousetraps, each one
with a ping-pong ball poised on the bait end of
the trap. Now imagine
tossing one ping-pong ball into the room and triggering
the chain reaction.
b. having students calculate how many cycles of letters
it would take, in a high
school of 1000 students, to make sure everyone received
a chain letter.
3. Two excellent activities (half-life simulation and understanding
isotopes)
are included in the ChemCom unit on radioactive
decay. (See References for
publisher information.)
Language of Chemistry
1. Glossary
alpha particles(a, 42He)
a nuclear particle containing two protons and two
neutrons with a mass number of four (4.0026 u). An alpha particle is
ide e as one
of the reactants. Such a reaction is self-sustaining, once begun. In
nuclear fission, the chain reaction is started with neutrons that split
uranium nuclei, which, in turn release more neutrons to sustain the
reaction.
control rods cylinders usually made of neutron-absorbing
material, such
as boron or cadmium, which may be lowered into a nuclear fission reactor
to control the speed of the reaction by slowing, or halting the chain
process.
critical mass the minimum mass of radioactive
material needed to sustain
fission.
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