Physics 6.6 - 6.9 Flashcards
What is contamination and is it dangerous
Contamination is when radioactive particles get onto other objects. It isn’t dangerous unless those particles decay which will irradiate the object
What is irradiation
Irradiation is the process by which an object is exposed to radiation
Name 4 types of ionizing radiation
Alpha
Beta
Gamma
Xray
Name 4 types of non ionizing radiation
Infra red
radio waves
micro waves
Visible light
Explain why radiotherapy is used
Radiotherapy is used to treat patients with cancer by either placing radioactive materials near them or Inside them. Beta radiation or gamma radiation is used
Explain why medical tracers are used
They are used to check if organs are functioning properly by either injecting or making a patient swallow a radioactive material that emits radiation. We then track that radiation and see if its being absorbed by organs as it should be to check if they’re functioning properly. We usually use gamma radiation for this
When is radiotherapy and medical tracers used
It is used when the benefit outweighs the risk as irradiation is dangerous
What is nuclear fission
Nuclear fission is when a parent nuclei absorbs a neutron which causes it to be unstable so it splits in to daughter nuclei and releases neutrons and eneryg in the form of gamma radiation. This process can happen spontaneously which is rare or by absorbing a neutron
How do nuclear reactors generate electricity and control nuclear fission
After energy is produced from nuclear fission, it is used to heat up water turning it into steam which then turns a turbine connected to a generator to produce electricity. Nuclear reactors control the process of nuclear fission by placing control rods which absorb neutrons. This effectively slows down the reaction
State 3 pros of nuclear reactors
Nuclear fuels are cheap
They produce a steady amount of energy
They don’t produce greenhouse gasses
State 3 cons of nuclear reactors
Nuclear meltdowns can occur
Nuclear waste is expensive to get rid of
The initial setup cost is high
What is nuclear fusion
Nuclear fusion is when two nuclei fuse together forming a larger nucleus. The fusion of these particles release a lot of energy and lose little mass in the process which is why the product formed is slightly lighter than it’s supposed to be. The mass lost is converted into the energy released which is calculated by E = mc^2 where E is the energy released, m is the mass lost and c is the speed of light (9*10^16)
What conditions are required for nuclear fusion to occur and have we achieved it here on earth
High temperatures and pressures are required, we haven’t achieved it here on earth
Where does nuclear fusion occur
Nuclear fusion occurs in stars such as the sun
Why does it only happen under high temperatures and pressures
To overcome the forces of repulsion between the positive nuclei
