Chapter P7- Radioactivity Flashcards
What is the charge of an electron?
What is the charge of an neutron?
What is the charge of a proton?
What is the mass of both a neutron and a proton?
What happens to atoms that have a stable nucleus?
What does an atom do if it nucleus is unstable?
What device do you use to detect radiation?
-1.
0.
+1.
1.
They don’t change.
Then it emits radiation to make itself more stable.
A Geiger counter.
What are the three types of radiation?
Describe what the first type of radiation’s features are?
Describe what the second type of radiation’s features are?
Describe what the third type of radiation’s features are?
Alpha, beta and gamma.
It is made up of 2 protons and 2 neutrons. It has a charge of +2 and range in air is 5-10 cm. It can also be absorbed by paper.
It is made up of a high speed electron and has a charge of -1. It’s range in air is 1m and can be absorbed by a thin piece of aluminium.
It is made up of an electro magnetic wave and has a charge of 0. It’s range in air is infinite and can be absorbed by 5cm lead/1-2 metres of concrete.
What does the top number of an atom mean?
What does the bottom number of an atom mean?
What are the 2 types of numbers in an alpha particle?
What are the 2 types of numbers in beta particle?
What is shown in gamma decay?
How does a Geiger counter measure radiation?
Where is every count shown?
Mass number (protons and neutrons added together).
Proton number (number of protons usually the same as the number of electrons).
4 mass number.
2 proton number.
0 mass number.
-1 as it’s charge.
It doesn’t show the two numbers because the nucleus doesn’t change. It only takes away excess energy.
By registering every time a radiation ionises the air inside the tube.
On the display.
What is ionisation?
What does irradiated mean?
What three things can block radiation?
In what three ways can workers who use ionising radiation reduce their exposure?
What is half life?
Describe half life in radioactive materials?
What is activity in radiation?
What is this measured in?
When the radiation knocks an electron from the atom causing the atom to become charged.
When an object is exposed to radiation it is irradiated. It doesn’t become radioactive however.
Paper, aluminium and lead (and possibly thick concrete).
By keeping as far away as possible from the source.
Spending as little time as possible in risk areas.
Shielding themselves by staying behind concrete barriers.
The amount of time it takes for the radioactivity to drop by a half.
They all follow the same pattern of decay, but have different half lives.
The activity of a source is the number of unstable atoms in a source that decay per second.
Bacquerel (Bq). 1 Bq is 1 decay per second.
What is count rate in radiation?
What is the first type of half life?
What is the second type of half life?
What are the original atoms called in radiation?
What are the new atoms called in radiation?
The count rate is the way we measure activity. It’s the number of counts per second that enter the Geiger counter. This is proportional to the activity.
The average time it takes for the number of nuclei (so the mass of the parent atoms) of the isotope in the sample to halve.
The average time it takes for the count rate from the isotope in the sample to fall to half its initial value.
Parent atoms.
Daughter atoms.
What do radioactive tracers do?
What does the tracer contain?
What do gamma cameras do?
What is radiotherapy used for?
What is used in radiotherapy?
What are radiative implants used for?
What is used in radiative implants?
They trace the flow of a substance through an organ.
A radioactive isotope that emits gamma radiation.
They are used to take images of internal body organs, by the patient being injected with a radioactive substance.
Gamma radiation in a narrow beam is used to destroy cancerous tumours.
The radiation emitted from radioactive isotope of cobalt (half life of 5 years).
They are used to destroy cancer cells in tumours.
Beta or gamma emitting isotopes are used in the form of small seeds or tiny rods.
What sources of background radiation are natural?
What sources of background radiation are man made?
What are the five main parts of a nuclear power stations (in order)?
What is nuclear fission?
What does this then form?
How can nuclear fission occur?
What is released in nuclear fission?
What else is emitted?
Ground, air (radon) and cosmic.
Medical, food and drink, nuclear weapons, nuclear reactors and air travel.
Furnace— Boiler—Turbines—Generator—Transformer—Nuclear reactor.
When a large unstable nucleus splits.
Two smaller nuclei roughly equal size.
Not often naturally but if the unstable nucleus absorbs a neutron.
Heat energy.
2 or 3 neutrons and gamma waves.
What is the end product called in nuclear fission?
What does the concrete shield do in a nuclear reactor?
What is the nuclear fuel made out of?
What does the moveable control rod do?
What two ways does water act as?
What is nuclear fusion?
What happens when this occurs?
Fission product.
Prevents gamma radiation escaping.
Uranium/plutonium (usually isotopes of them).
Absorb any surplus neutrons to keep the chain reaction under control.
A coolant to remove the heat from the fuel rods.
A moderator slowing down the neutrons through collisions so they don’t go in to cause collisions in other nuclei.
The joining of 2 light nuclei to form one heavier nucleus.
Some of the original mass may be converted into energy.
What is background radiation?
What is background radiation measured in?
What two things vary the amount of background radiation?
What is ionisation?
The radiation around us all of the time.
Sieverts (Sv). 1,000 mSv= 1Sv
1,000,000 uSv= 1Sv.
Location and occupation.
The formation of ions (the loss or gains of electrons).
