Simplified P2 - Nuclear Radiations Flashcards
Why are atoms neutral in charge?
They contain the same number of protons and electrons, this means they are neutral.
What does ionisation involve?
Ionisation involves gaining or losing electrons.
What happens if an atom loses an electron?
It becomes positively charged.
What happens if an atom gains an electron?
It becomes negatively charged.
What can the formation of ions cause?
The formation of ions can cause chemical reactions.
What are the issues with the chemical reactions caused by the formation of ions?
Such reactions may disrupt the normal behaviour of molecules inside the body, e.g. they may cause strands of DNA to break or change; protein molecule may change their shape and these effects are potentially harmful.
Where do alpha,beta and gamma radiations come from?
These radiations come from the nucleus of an atom.
What radiation causes the most ionisation and what causes the least?
Alpha radiation causes the most ionisation
Gamma causes the least ionisation.
What radiation has the most penetrating power, and what has the least?
- Alpha has the least penetrating power, it is stopped by 2cm of paper.
- Beta has a range of about 1 m and is absorbed by a few mm of aluminium
- Gamma is much more penetrating, a few CM of lead can stop most of it, however some can pass through several meters of lead and concrete.
In experiments carried to identify the type of radiation you are looking for, what type of radiation must you always account for?
You must always account for background radiation in the experiments done to identify the type of radiation via its penetrating power.
What type of radiation do smoke alarms contain?
Smoke alarms contain alpha radiation.
How do smoke alarms work?
- Radiation ionises the oxygen and nitrogen atoms in air which causes a very small electrical current that is detected
- When smoke fills the detector in the alarm during a fire, the air is not so ionised, the current is less and the alarm will sound.
How can you control thickness in a paper rolling mill?
Thickness in paper can be controlled using a source of beta radiation and a detector:
- The amount of radiation passing through the sheet is monitored and the pressure on the rollers is adjusted accordingly.
How can Gamma radiation be used practically?
- Gamma radiation kills microbes and bacteria, so it can be used for sterilising medical instruments.
- Gamma radiation can be used to check for leaks in pipes and welds.
- Beta or gamma can be used to trace the passage of blood around the body, using a gamma or beta source.
What is plutonium?
Plutonium is a waste product from nuclear reactors which can be used to make nuclear weapons.
