2.8 HALF LIFE

Question 1

WHAT IS HALF LIFE?

Answer 1

The time taken for the number of radioactive nuclei to reduce to one half of its initial value

Question 2

HOW CAN WE CALCULATE HALF LIFE?

Answer 2

Decay curves (graph)

Question 3

WHAT IS CARBON DATING USED FOR?

Answer 3

To estimate the age of an object once it has died

Question 4

WHAT IS THE HALF LIFE OF CARDON-14?

Answer 4

5700 years

Question 5

WHAT IS THE USE OF RADIOACTIVE MATERIAL IN RADIOACTIVE TRACERS?

Answer 5

Radioactive tracers are used for medical imaging. A radioactive material is injected or ingested into the body and radiation detectors placed outside the body detect the radiation emitted. Cameras use this information to produce detailed images of inside the body

Question 6

WHAT IS THE USE OF RADIOACTIVE MATERIAL IN CANCER TREATMENT?

Answer 6

A radioactive material can be placed inside the tumour to kill the cancer cells. The radiation emitted needs to be:
- strongly ionising so that it kills the cells
- moderately penetrating so it can pass through the tumour to kill the cancer cells without damaging healthy ones.