3.3 Flashcards
(27 cards)
Ionising radiation
3
Helpful but harmful
Certain parts of the electromagnetic spectrum we use in our daily lives pose hazards that are specific to the type of electromagnetic wave
•cancer is diagnosed / treated using this
Radiotherapy
The treatment of cancer using ionising radiation-this damages/destroys cells in the area being treated,making it impossible for the cells to continue to grow
2 examples of transverse waves, and what do they form?
•x rays
•gamma rays
Form electromagnetic radiation
What does an alpha particle consist of?
2 protons
2 neutrons
What is beta?
An electron
What is gamma?
Very high-energy (ionising) electromagnetic wave
Alpha mass compared with proton
4
Beta mass compared with proton
1/2000
Gamma mass compared with proton
0
Alpha charge compared with proton
+2
Beta charge compared with proton
-1
Gamma charge compared with proton
0
How ionising is alpha?
Very
How ionising is beta?
Weakly
How ionising is gamma?
Very weakly
Penetrating power of alpha
Absorbed by skin,thick paper or 10cm of air
Penetrating power of beta
2
Passes through skin,thin aluminium or a few metres of air
•absorbed by lead
Penetrating power of gamma
2
- Very penetrating.
* Partly absorbed by dense materials like lead or concrete
What are gamma rays detected using?
A gamma camera.
The use of high-energy (ionising) radiation….
Can be dangerous and needs to be monitored
What do people who work with radiation wear?
Film badges
Why are film badges monitored regularly to check radiation?
If molecules in living cells are damaged,the cells may die,turn cancerous or stop working permanently.
•they give info to help limit exposure
x ray - diagnosing medical disorders
pass easily through flesh but not denser (bone)
detected using photographic film
construction of a film badge
paper. lead
plastic cover. aluminium.
