6.6 Radioactivity at work

Question 1

Which type of radiation is used in a smoke alarm?

Answer 1

Alpha source, not dangerous as very poorly penetrating. Source needs a half life of several years.

Question 2

What are beta sources used for?

Answer 2

Thickness monitoring in the manufacture of things like paper or foil because alpha particles would be stopped by the thin sheets and gammer would go through it. Source needs a half life of many years.

Question 3

What are gamma and beta sources both used in?

Answer 3

traces in medicine. needs source of a few hours, so person not exposed to unnecessary radiation

Question 4

Why isnt alpha source used as a tracer in medicine?

Answer 4

They are very poorly penetrating so would not be detected outside the body. They are very ionising they would be damaging to the patient.

Question 5

What is radioactive dating used for?

Answer 5

To find the age of ancient material

Question 6

What is carbon dating used for?

Answer 6

Find the age of ancient organic material (wood)

Question 7

What is uranium dating used for?

Answer 7

Find the age of indigenous rock