Physics - Radiation Flashcards
Parts of an atom
The atom contains a nucleus at the center. The nucleus contains most of the mass of the atom. If contains Protons and Neutrons. Electrons are in orbit round about the nucleus.
Particles and their relative
Proton: +1
Neutron: 0
Electron: -1
What is an example of a radioactive element?
Uranium
Alpha: symbol and what it is
Check jotter
It has two Protons. A helium nucleus.
Beta: symbol and what it is
β
A high speed electron.
Gamma: symbol and what it is
γ
A high frequency electromagnetic wave.
Alpha: what it is absorbed by
Paper or a few cm of air.
Beta: what it is absorbed by
A few mm of aluminium.
Gamma: what it is absorbed by
Only cut down, not completely absorbed by several cm of lead.
The number of radioactive nuclei that decay in 1 second is called the activity of the source. Activity formula:
Activity= number of nuclei decaying ÷ time taken
A=N÷t
activity is measured in Bq Becquerels
What is ‘ionisation’
Ionisation is the breaking up of a neutral atom into positive and negative pieces.
Which kind of radiation produces the most ionisation.
Alpha
What damages are caused by radiation?
Different types of cancers, particularly thyroid cancer.
Birth defects due to genetic damage.
Death from acute radiation sickness.
Half-life
The time it takes for the number of nuclei in a sample to halve.
Advantages on nuclear fuels
Nuclear power produces no CO2 (carbon dioxide). It only produces very little.
It lasts longer.
