stuff I didn't know abt radiation

Question 1

what is the name of the equipment used to measure ionising radiation?

Answer 1

Geiger-Muller tube or GM tube

Question 2

when asked for safety precautions when handling radioactive material:

Answer 2

1. handle at a safe distanace
2. limit exposure time
3. do not handle with bare hands - tongs
4. store in a lead lined container

Question 3

What is carbon dating?

Answer 3

Using the half-life of something to calculate its age, using carbon-14 as a reference

Question 4

Why is it impossible to use carbon dating on fossils?

Answer 4

1. it is impossible to distinguish between background radiation and radiation from fossil the activity from the fossil would be too small
2. minerals would have displaced the carbon

Question 5

when asked for the structure of an alpha particle just say:

Answer 5

helium nucleus

Question 6

why is it safe to sterilise food or equipment with gamma rays?

Answer 6

1. kills microorganisms and pathogens
2. the food is not contaminated after it has been irradiated

Question 7

Explain why it is safe to have an alpha emitter in a smoke alarm?

Answer 7

alpha is weakly penetrating and is absorbed by the casing.

only has a few cm range in air.

Question 8

How do smoke alarms w alpha radiation work?

Answer 8

The alpha particles ionise the air, creating a current. when smoke enters the smoke alarm, this current is disrupted and the alarm rings.

Question 9

background radiation definition

Answer 9

low level radiation that is always present in the environment

Question 10

safety precautions for using radioactive material in medicine or industry

Answer 10

• use an isotope with an appropriate half-life so that it doesn’t stay radioactive for too long
• stored in a lead-lined box
• handled w care - tongs and safety equipement

Question 11

why is alpha radiation used in radiotherapy/ when they inject radioactive material so that cancer cells are killed?

Answer 11

• alpha radiation is highly ionising so kills the cancer cells well
• only a short range in the air so cannot spread to environment
• weakly penetration so will not spread past the area injected and won’t affect other parts of the body

Question 12

Why are gamma rays used in medical imaging?

Answer 12

weakly ionising so won’t cause mutations in cells

highly penetrating and good range in air so picked up by radioactivity detectors