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Beta Particles.
What is a Beta Particle?
A beta particle (also written as β-particle) is the same
as an electron.
It is often called a high energy electron because it is very fast moving.
A beta particle comes from the nucleus of an atom! It has a
charge of -1 and very little
mass (only 1 ÷
1840 as big as a proton).
The e shows that the particle is an electron.
A beta particle is given a mass number of zero because the
mass is very small compared to a proton or a
neutron.
What are the Properties of a Beta
Particle?
1. A beta particle has a negative charge because it is an electron.
2. A beta
particle has less
mass than an alpha particle but
more mass than a gamma
ray. See the three types
of radioactivity.
This means that
(i)
beta particles have
more penetrating ability than alpha particles
but less penetrating ability than
gamma rays.
(ii) beta
particles are less
ionising than
alpha particles
but more
ionising than gamma rays.
Where do Beta
Particles come from?
Beta
particles may be
emitted from the nucleus
during the
decay of either big
or small nuclei. See some examples.
How can the Direction of a Beta
Particle be Changed?
The negative
charge on the beta particle
means that it will be
deflected by a magnetic field or an electric
field (like the
charged
droplets in an inkjet
printer). A beta particle
will be deflected
more than an alpha particle
(because of its smaller mass)
and in the opposite
direction (because of its negative
charge).
Links
Radioactivity
Revision Questions
gcsescience.com Physics Quiz Index Radioactivity Quiz gcsescience.com
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