Least Ionising, most
penetrating-few cm of
lead, no charge
Beta
Mid Ionising, Mid
penetrating-thin metal
, negative charge
Alpha
Most Ionising, Least
penetrating-paper/skin,
positive charge
What is nuclear fusion?
When 2 hydrogen nuclei
in the atoms are brought
close together and fuse-
releasing energy
What are Isotopes?
Atoms of an element that have
a different mass number due to
a different number of neutrons
E=mc²
E=ENERGY PRODUCED
m=change in mass
c=speed of light
calculates the amount
of energy released
during nuclear fission
and fusion
Half life- time
taken for number
of atoms to halve
from decay
Radioactive Decay- the spontaneous
change in an unstable element, giving out
alpha, beta or gamma radiation. Alpha
and beta emission result in a new
element
Radiation Sources
Natural
84%
50% from
radon gas in
the ground
12% from
cosmic
rays
9.5% from
food and
drink
13% from gamma
rays from the
ground and
buildings
Artificial
15% medical
16%
What is nuclear fission?
The process when a nucleus of
uranium-235 breaks apart,
releasing energy, when it
absorbs a neutron
Nuclear fuel-in a nuclear
reactor, each uranium
atom in a fuel rod
undergoes fission and
releases energy when hit
by a neutron
Radiotherapy-using high
doses of ionising to kill
cancerous cells/x-rays in the
body
Sterilisation-gamma
radiation kills
microorganisms through
packaging in medical
equipment
Why is ionising radiation dangerous?
Ionising radiation has the energy to break
molecules in the cells in the body into
ions. These ions can then take part in
chemical reactions that might damage the
body. If the ionising radiation affects DNA
molecules, this may cause the cell to be
killed or behave abnormally, which can
cause cancer.