Uses of Radioactivity

Question 1

List the uses of Radioactivity

Answer 1

• -> Smoke detectors
• ->Thickness monitoring
• -> Sterilisation of equipment
• ->Radiotherapy

–>Tracers

Question 2

Explain the use of smoke detecters

Answer 2

• ->some SD contain rad. iso. which emit alpha radi.
  - -> alpha part. ionise AIR within SD
  - -> allowing current
  - ->when smoke enters alpha part. absorbed
  - ->trig. alarm

Question 3

Explain the use of thickness monitoring

Answer 3

• -> Material moves thru. beta source
• ->the amount of part. that can penetrate monit.
  - -> If material gets thicker
  - -> more particles absorbed(less get through
  - -> If material thinner
  - ->more get through

                       --> allows machine to make ad. 2 keep thickness CONSTANT

Question 4

Why is beta radiation used in thickness monitoring

Answer 4

• -> bcus alpha particles never get thru(even for paper)

- -> gamma rays ALL would go thru( no diff. sense)

Question 5

Explain the use of tracers

Answer 5

–> added to fluid to monitor it(e.g:blood,pipeline)

Question 6

How do we ensure safety when using tracers?

Answer 6

• ->amount kept to a minimum(reduce exposure)
• ->Isotopes with short HL (can carry out, but no lt harm)
• ->Gamma radiation used:
  - -> highly penetrating (less likely to be absorbed)
  - ->weakly ionizing (less harm)

Question 7

Explain the use of sterilisation

Answer 7

• -> exposing to gamma rays
• -> kill bac. + destroy viruses
• ->able to penetrate ar. that would other. not prop. ste.

Question 8

What is radiotherapy

Answer 8

–>treatment of cancer using radiation

Question 9

Explain the process of radiotherapy

Answer 9

–>kills living cells

Question 10

Why are gamma rays used in radiotherapy?

Answer 10

–>minimise harm to HEALTHY tissue