Physics Test 2
How is radioactive decay triggered?
It is spontaneous.
What is alpha radiation?
Alpha radiation produced by alpha decay. Releases helium nuclei, also known as alpha particles.
What is beta radiation?
Produced by beta decay. Releases electrons, also known as beta particles.
What is gamma radiation?
Produced by gamma decay. It is a high-energy electromagnetic wave with a higher frequency than X-Rays.
What are beta particles?
Electrons.
What can you use to detect radiation?
A geiger counter
Examples of things that release radiation around us:
Food
The sun
Rocks
Radon
Which type of radiation is made up of high energy electrons?
Beta radiation
Which is the most penetrating type of radiation?
Gamma radiation
Which is the least penetrating type of radiation?
Alpha Radiation
What is fired into a nucleus to cause nuclear fission?
A Neutron
What is nuclear fission?
Nuclear fission is the process where the nucleus of an atom splits into two or more smaller nuclei and other particles.
What is nuclear fusion?
Nuclear fusion is the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
Where does nuclear fission happen?
A nuclear reactor
In nuclear fission what happens to the split nucleus?
This creates an unstable nucleus.
What (in steps) happens in nuclear fission?
1. Nucleur Fission is the splitting of a large nucleus into a smaller nucleus
2. Fission usually requires the absorbtion of a neutron to destabalise the nucleus
3. A heavy nucleus splits into 2 smaller nuclei, 2 or 3 neutrons plus gamma rays
4. Thermal energy is released during a fission reaction
5. The neutrons may cause a chain reaction
6. A chain reaction is controlled in a nuclear reactor
What (in steps) happens in nuclear fusion?
1. Nuclear fusion is the joining of small nuclei into large nuclei
2. During the process, some of the mass is converted into energy and released as heat/thermal energy
3. Fusion of hydrogen forms helium
What kind of reaction happens during nuclear fission?
Chain reaction
Gamma decay does not emit any?
Protons or neutrons.
What is the half life of something?
The amount of time that it takes one half of the atoms present to decay
What are the 2 types of exposure to radiation.
Irradiation
Contamination
How many protons and neutrons are found in an alpha particle?
2 Protons + 2 Neutrons
Why do things radiate?
To make the nucleus more stable
In radioactive decay, we cannot predict when an individual atom will emit what?
ionising radiation
What unit is the activity of a radioactive substance measured in?
The becquerel
Why are nuclear reactors needed?
In nuclear fission there is a lot of energy being emitted so it needs to be used/controlled
What is a example of nuclear fusion?
A hydrogen 1 fusing with a hydrogen 2 to make a Helium 3
Does nuclear fusion release any energy?
Yes it releases tons
What are the properties of a alpha particle?
+2 charge, stopped by paper, high ionisation
What are the properties of a beta particle?
-1 charge, a few mm of metal, medium ionisation
What are the properties of a gamma particle?
0 charge, reduced by lead, lowest ionisation
What is ionisation?
Ionisation is the process by which an electron is removed from an atom or a molecule