Radiation in the real world
Every chemical element will have stable or
unstable isotopes. As some are unstable they
will undergo radioactive decay and emit either a
subatomic particle or electromagnetic radiation.
What types of radiation are there?
An unstable atom will emit one of three types of
radiation.
Alpha radiation- An alpha particle consisting
of two protons and two neutrons is emitted.
Beta radiation- A high energy electron is
emitted.
Gamma Radiation- High frequency
electromagnetic radiation is emitted.
When this
radiation is
emitted it will
interact with
obstacles in its
path for
example the air
or body tissue.
These interactions could be either beneficial or
detrimental. The varying degrees of penetration
are shown in the diagram.
The varying penetration of
radiation. Image taken
from www.ndt-ed.org
Radiation can be used in many practical areas of
science, namely in medical physics for the
treatment of cancer.
How does radiation work?
Every substance in the universe can be broken
down into its smallest unit, these units are called
atoms. Atoms consist of several sub atomic
particles. These are electrons (negative charge),
protons (positive charge), and neutrons (no charge
ie neutral).
The protons and neutrons
make up the nucleus at the
centre. The nucleus has a
net positive charge. The
electrons are contained
within energy levels or shells
around the nucleus and have
a negative charge.
The total combined charge of an atom has to be
neutral, therefore the number of protons and
electrons will be the same. This doesn’t however
restrict the number of neutrons that can be
present in an atom as they contribute no charge.
If an atom of a certain element has a varying
number of neutrons the atom is said to be an
isotope of that element.
The Atom. Image taken from
www.Danieltrimpey.com
