Topic 6 - Radioactivity - Uses Of Radioactivity Flashcards
What radioactive element is used in smoke alarms?
Americium
Americium has a half-life of 432 years and is an alpha emitter.
What is the half-life of Americium?
432 years
What type of radiation does Americium emit?
Alpha radiation
How does Americium in smoke alarms detect smoke?
Alpha particles ionise air particles, creating a current that drops when smoke enters.
What is the effect of smoke on the circuit of a smoke alarm?
The current drops, causing the alarm to sound.
What type of radiation is used to irradiate food?
Gamma rays
What is the purpose of gamma rays in food irradiation?
To kill bacteria and sterilise food
How do gamma rays affect the ripening of fruit?
They delay the ripening process.
What is the purpose of sterilisation of equipment using radiation?
To kill all microbes present on the equipment.
Which type of radiation is commonly used for sterilising medical equipment?
Gamma radiation
What type of radiation is beta radiation?
Mildly penetrating
What is the role of beta radiation in gauging thickness?
To detect changes in thickness of materials like paper.
How is beta radiation used in paper production?
A source and receiver are placed on either side of the paper to measure electron reception.
What happens if there is a drop or rise in received electrons during gauging?
It indicates a change in thickness, suggesting a defect.
How is radiation used in the diagnosis of cancer?
By consuming or injecting a gamma emitter that reveals tumours.
