The Half-life
of Diceis a useful illustration of the random nature of radioactivity
and produces a good graph to plot.
Take ten bags
with 100 x 1cm3 cubes in each.
One side of each
cube needs to be painted black (best done before you cut them up if
you are making them in the technology lab!)
Give the bags
of 'dice' are to small groups of pupils.
They must throw
the dice into a small tray and remove any that fall 'black face upward'.
Then they must
count and record the number remaining and throw them again.
This is repeated
until all are removed.
The results can
be assimilated using a simple spreadsheet package.
In this way a random
decay with a probability of 1 in 6 can be plotted with 1000 events investigated.
Links with the mathematics department to work on probability are a possibility
here.
Again showing
the random nature of decay the following simulation popping
popcorn works well. (Care with safety! … Do a full
risk assessment!).
Pre-heat a popcorn
popper.
Mark a few of
the kernels with a felt-tipped pen.
Place about 20
popcorn kernels in the air popper. (Using only a few kernels will prevent
the kernels from being obscured by the popped corn).
Pop the popcorn.
Record the time
it takes for a coloured kernel to pop.
Repeat with fresh
kernels.
There is no
way to predict the exact time at which a coloured kernel will pop,
but it is possible to determine the time it will take most of them to!
Transmutation
can be simulated by playing a game. You need a supply of two sets of
coloured balls or beads. The beads are placed in a bowl to represent
the nucleus of an atom. Beads/balls representing the particle emitted
are taken out and the remaining nucleus' characteristic can then be
worked out by counting the number of protons and neutrons left in the
bowl. Its name can be looked up on a periodic table.
An 'exchange pot'
needs to be available so that beta and positron emission can be modelled.
A card explaining the rules must be put with the 'pot'. What ever represents
a proton can be exchanged for a neutron and a positron and whatever represents
a neutron can be replaced by a beta particle and a proton.
