Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
14 Cards in this Set
- Front
- Back
|
Describe the ionisation effects of alpha radiation at certain distances? |
Alphas ionising effect is strong but since apha only has a range in air of a few cms ionisation ceases above alphas range in air |
|
|
Describe the ionising effect of beta radiation at certain distance |
Beta has a weaker ionising effect than alpha but it has a range of about a metre |
|
|
Describe the ionising effect of gamma radiation and its range in air? |
Gamma has a much weaker ionising effect than beat or alpha because gamma has no charge so isn't going to be attracted to atoms which means that they're less likely to hit them but it has an unlimited range in air |
|
|
What's a geiger tube? |
It's a device used to measure radiation and it's a sealed metal tube which contains argon gas at low pressure |
|
|
What's the dead time of a geiger tube? |
It's the time taken for it to regain it's non conducting state which is usually about 0.2ms which means that another parties which enters the tune in this time won't be counted |
|
|
What happens to the count rate for alpha when you increase the distance? |
It decreases and above a range of about 3cm it drops suddenly because all alpha particles have the same kinetic energy which means that they will travel a similar distance |
|
|
What happens to the count rate for beta radiation as you increase the distance? |
As the distance increases the contract rate gradually decreases since beta particles have varying kinetic energies which means that they will travel different distances in air. Above about 1m the count rate will drop to the background count |
|
|
What happens to the count rate for gamma radiation as you increase the distance? |
Ut gradually decrease because the radiation spreads out more in all directions |
|
|
What are examples of background radiation? |
Cosmic rays and radon gas |
|
|
What is the half life? |
It's the time taken for a radioactive isotope to decrease to half its original mass |
|
|
What's the activity? |
It's the number of nuclei which disintegrate per second |
|
|
What's the binding energy? |
It's the work required to separate a nucleus into its separate nucleons |
|
|
What's the mass defect? |
It's the difference between the mass of the separated nucleons and the nucleus |
|
|
Why does fusion need lots of energy? |
Because the atoms need to have enough speed and energy to overcome the electrostatic force between them and get close enough to each other for the strong nuclear force to have an impact on them |
