Radioactivity

Question 1

Name the 3 different types of radiation with their signs

Answer 1

Alpha radiation - α
Beta radiation - β
Gamma radiation - γ

Question 2

Beta radiation can easily pass through a hand. True or false?

Answer 2

False - some of the beta particles get trapped inside the body, some of them are able to go through the hand

Question 3

What is the definition of radioactivity?

Answer 3

Radioactivity occurs when a nucleus is unstable (an ion or an isotope). It gives off energy by emitting particles to reduce its overall charge. This process is random and spontaneous, and know as decay

Question 4

Alpha particles are made from 2 protons and 2 neutrons. True or false?

Answer 4

True. They have an overall charge of +2

Question 5

Gamma radiation has an overall positive charge. True or false?

Answer 5

False. Gamma rays are a wave, therefore they have no overall charge

Question 6

Give the 3 types of radiation in order of highest to lowest:

a) energy
b) penetration power
c) ionising power

Answer 6

highest - lowest

a) Gamma, Beta, Alpha
b) Gamma, Beta, Alpha
c) Alpha, Beta, Gamma

Question 7

Fill the blanks -
Alpha particles don’t travel ___ – because they have such a large mass. This means that they tend to _______ with plenty of other ____. Therefore, they cause a lot of __________ by pulling electrons off the atoms.

Answer 7

Fast
Collide
Atoms
Ionisation

Question 8

What is half-life?

Answer 8

The time it takes for half of the radioactive nuclei to decay. REMEMBER - if the nuclei starts at 400, the when it reaches 200 a half-life has gone, then at 100 another half-life has decayed

Question 9

What shape is a half-life graph?

Answer 9

A curve, never reaching 0