Alpha, Beta, Gamma Flashcards
How do you take account of background radiation in experiments?
Geiger counter in position without the source
Measure the count for a suitable period i.e. 3 minutes
Repeat, take a mean
Minus this value from the count rate when the source is present
Ionisation
Process by which an atom acquires a positive or negative charge by losing or gaining electrons
Forming an ion
2 main ways that Alpha, Beta, and Gamma differ
Ionising Power
Penetrating Range
Ionising Power
How many ions produced per unit distance traveled in a particular material
Penetrating Range
How far they can travel through materials
The thickness of a material needed to absorb them
Alpha charge
2e
Alpha nature
Helium nucleus
Alpha ionising power
High
Alpha range in air
Less than 0.02m
Alpha penetration range
Sheet of paper
Beta charge
-e
Beta nature
High energy electron
Beta ionising power
Medium
Beta range in air
1-2m
Beta penetration range
mm of aluminium
Gamma charge
0
Gamma nature
EM photon
Very short wavelength
Gamma ionising power
Low
Gamma range in air
Infinite
Gamma penetration range
cm of lead
More than 1 m in concrete
What is conserved in nuclear transformation equations?
Baryon number
Charge
Lepton number
Half Life (2 definitions)
Time taken for half of the unstable nuclei in a sample of an isotope to decay
Time taken for for activity of a sample to halve
Activity
Rate of decay of unstable nuclei
Radioactive decay is random- what does this mean?
Cannot predict when a particular nucleus will decay
Radioactive decay is spontaneous- what does this mean?
No external processes (i.e. pressure and temperature) influence the decay
If your half life graph levels off at a constant, what can you deduce?
Background radiation has not been deducted
