half life Flashcards
1
Q
define the half life of a radioactive isotope
A
the time it takes for the number of unstable nuclei to halve
2
Q
why are isotopes with long half-lives particularly harmful
A
they remain radioactive for much longer period of times
3
Q
state 2 uses of nuclear radiation in the medical field
A
- examining of internal organs
- controlling and destroying of unwanted tissue
4
Q
describe the nature of radioactive decay
A
random.
is determined by chance
impossible to predict
5
Q
how do you determine half life from a decay curve
A
see what time it took for number of unstable nuclei to decay
6
Q
what is the idea behind carbon dating
A
- all living things contain the same relative amount of carbon-12
- when the die, the carbon decays at a known rate
- by measuring amount of carbon remaining, age can be calculated
7
Q
the half life of a radioactive isotope is…
A
constant
