Types of radiation and their properties Flashcards
Name the types of radioactivity or radioactive decay.
Alpha particles (α) Beta particles (β) Gamma radiation (γ)
What is the symbol for an alpha particle?
4 He or 4 α
2 2
What is the symbol for a beta particle?
0 e or 0 β
-1 -1
What is the symbol for gamma radiation?
𝛾
Describe alpha particles.
Alpha particles are slow moving, heavy particles consisting of 2 protons and 2 neutrons. This means that they have a charge of +2 and a mass of 4 which is the same as a helium nucleus. They have low penetrating power and can be stopped by a few centimeters of air or a sheet of paper.
Describe beta particles.
Beta particles are fast moving electrons that are emitted by some radioactive nuclei when a neutron splits into a proton and an electron. This means they have a charge of -1 and a mass of 0. Beta particles have a medium penetrating power and are stopped by a thin sheet of aluminum or plastics such as perspex.
Describe Gamma radiation.
Gamma radiation is a high energy electromagnetic wave and not a particle. This means gamma rays have no mass and no charge. Gamma rays have a high penetrating power and it takes a thick sheet of metal such as lead, or concrete to reduce them significantly.
Describe what would happen to an alpha particle in an electrical field.
As expected, positive alpha particles are attracted to the negative plate.
Describe what would happen to beta particles in an electrical field.
Negative beta particles are attracted to the positive plate.
Describe what would happen to gamma rays in an electrical field.
Gamma rays are unaffected as they have no charge.
Why is the deflection of an alpha particle much smaller than the beta particle in an electrical field of equal strength?
The deflection of an alpha particle is much smaller than that of the beta particle, in an electrical field of equal strength, as the alpha particle is much greater in mass.
What is the speed of an alpha particle?
It has a slow speed.
What is the speed of a beta particle?
It has a fast speed.
What is the speed of gamma radiation?
It has the speed of light.