Activity Flashcards
1
Q
Equation for activity
A
A = kN, where N = number of radioactive atoms present
2
Q
1 ppb
A
= 1 part per billion
= 1 x 10^-9
3
Q
Using the same method for a sample of lava produced just 10 years ago, results in an apparent age of 2000 years. Suggest a reason why this might be the case.
A
Some Ar can be trapped from the atmosphere into the molten lava and thus does not originate from 40K decay. This small error becomes significant when only a little 40K has decayed, i.e. at short time scales.
4
Q
Avogadro’s constant
A
6.022 x 10^23
5
Q
Activity =
A
“rate of decay”
6
Q
Half life
A
The amount of time required for the number of radioactive nuclei to be halved as a result of radioactive decay
