Half life

Question 1

What is measured using activity and half-life?

Answer 1

How quickly unstable nuclei decay

Question 2

What do Radioactive sources contain?

Answer 2

Radioactive isotopes that give out radiation from the nuclei of their atoms.

Question 3

What can you predict if there are lots of nuclei?

Answer 3

you can predict how many will have decayed in a given time based on the half-life of the source.

Question 4

What is Activity? And what is it measured in?

Answer 4

the rate at which a source decays. It is measured in becquerels, Bq.

Question 5

What is 1 Bq?

Answer 5

1 decay per second

Question 6

What can Activity be measured with?

Answer 6

Geiger-Müller tube which clicks each time it detects radiation

Question 7

What happens each time a radioactive nucleus decays?

Answer 7

1 more radioactive nucleus disappears

Question 8

What is The Half Life?

Answer 8

the average time taken for the number of radioactive nuclei in an isotope to halve

Question 9

What is a Short half life?

Answer 9

means activity falls quickly, because the nuclei are very unstable and rapidly decay.
Dangerous at start but quickly become safe.

Question 10

What is a Long half life?

Answer 10

means activity falls more slowly because most of the nuclei don’t decay for a long time.
Dangerous because nearby areas are exposed to radiation for years.