Radioactivity

Question 1

Radioactive isotopes

Answer 1

Where the nucleus is unstable so it decays and emits radiation

Question 2

Background radiation

Answer 2

1. Around us all the time
2. Radiation from space
3. Radiation due to human activity

Question 3

Radiation causes

Answer 3

Ionisation by bashing into atoms and knocking electrons off them

Question 4

Alpha

Answer 4

1. 2 protons and neutrons
2. Strongly ionising
3. They deflect by electric and magnetic fields

Question 5

Beta

Answer 5

1. Moderately ionising

2. Also charged

Question 6

Gamma

Answer 6

1. No mass just energy
2. Weakly ionising
3. Emission always happens after beta or alpha decay

Question 7

Medical tracers (beta and gamma)

Answer 7

1. Radiation penetrates body tissues
2. Computer converts reading to an on screen display showing where it is coming from
3. Has a shirt half-life

Question 8

Industrial tracers (gamma)

Answer 8

1. If there’s a crack in the pipe then the gamma source will collect outside the pipe and the detector will show extra high radioactivity
2. Has a short half-life

Question 9

Radioactive dating of rocks

Answer 9

By measuring amount of a radioactive isotope left in a smaller and knowing its half-life you can deduce how long it has been around

Question 10

Activity

Answer 10

Activity if a radioactive source is equal to the number of decays per second

Question 11

Half-life

Answer 11

The average time taken for half of the original mass of the sample to decay