[Part 2]- P7-Atomic structure ☣️⚛️ Flashcards
What is radioactive decay?
Hint: isotopes decay into…
- Radioactive decay, is when unstable isotopes decay into elements and give out radiation as they try to become more stable.
- They then try to balance the number of protons and neutrons, in their nucleus.
How is alpha radiation used in smoke detectors?
Hint: ionises, smoke in air—>current stops, alarm sounds
- It ionises air particles, causing a current to flow.
- If there’s smoke in the air, it then binds to the ions- which means the current stops, and the alarm sounds.
What does a Geiger counter do?
Hint: particle of _________ enters the tube.
A geiger counter detects radioactivity, and clicks each time a particle of radiation enters the tube.
What is background radiation?
- background radiation, is radiation that exists around us all the time
Name five places where background radiation can come from [5]
Hint: cosmic
- radon gas from the ground
- food and drinks
- buildings and the ground
- artificial sources
- cosmic rays
Can you name some artificial sources of radiation?
- nuclear power and weapon testing
- medical reasons (e.g- chemotherapy)
What is Bequerls, Bq ?
- Bequerels is the count rate of radioactivity
What is ionisation?
- Ionisation causes atoms to gain or lose electrons, which forms ions.
What is irradiation?
Irradiation is exposure to (nuclear) radiation
What is contamination?
- Contamination is when radioactive particles, get into objects.
- [contamination is the unwanted presence of materials, that contain radioactive atoms on other materials]
What is the difference between irradiation and contamination?
Irradiation is exposure to radiation ; Contamination is when radioactive particles, get into objects.
What ionising power does alpha, beta and gamma radiation?
Hint: most
Alpha=most ionising power
Beta= lower ionising power
Gamma= lowest ionising power
What is the penetrating power of alpha, beta and gamma radiation?
Hint: lowest, …, …
Alpha= lowest penetrating power (because it ionises the air)
Beta= lower penetrating power
Gamma= highest penetrating power [and is the most penetrating]
What is the range in air of alpha, beta and gamma radiation?
Alpha= a few cm in the air
Beta= several metres in the air
Gamma= long distances through the air
What can be used to stop: alpha, beta and gamma radiation?
Alpha= stopped by paper and skin
Beta= stopped by thin, aluminium foil
Gamma= lead and thick concrete
What are ways to reduce the risk of irradiation?
Hint: remote control, keep sources, stand
- keep radioactive sources in lead- lined boxes
- stand behind barriers when using radioactive sources
- in industries, the radioactive source may be in a different room and remote controlled.
What are ways to reduce the risk of contamination?
Hint: protective
- use gloves or tongs when handling radioactive sources
- in industrial purposes, wear protective suits to stop breathing in particles.
Why are beta and gamma the most dangerous sources of radiation, outside of the body? (Compared to alpha radiation)
- beta and gamma can penetrate through the body, and get to delicate organs
- However, alpha radiation is less dangerous as it can’t penetrate the skin + is easily blocked by a small air gap
Inside of our bodies, which source of radiation is the most dangerous and why?
Hint: localised area
- Inside of our body, alpha sources are the most dangerous because they do damage in a localised area.
- This is why contamination, compared to irradiation is a major concern when handling alpha sources.
Inside of our bodies, which is the lower danger of radiation? Why
Hint: radiation is absorbed over a wider area
- Inside of our bodies, beta sources are the less dangerous because radiation is absorbed over a wider area. Meaning some passes out of the body
Which type of radiation, is the least dangerous, inside of our body?
Hint: think about ionising power
- But overall, gamma sources are the least dangerous inside of our body.
- This is because they pass straight out, due to having the lowest ionising power.
Why is peer reviewing important?
Hint: published + shared
- Peer reviewing is important, because scientists findings’ can be published and shared, so their findings can be checked by other scientists.