2.8 Flashcards
1
Q
What is half life
A
The time takes for half the unstable atoms to decay. The time it takes for the activity to halve from its original value
2
Q
What is the activity?
A
A measure of number of radioactive decays per second and measured in Bq
3
Q
What does the activity of a radio active material sample depend on?
A
The number of radioactive/ unstable atoms present
The half life of the atoms
4
Q
Half life key points-
A
isotopes with very long half lives remain radioactive for a long time and isotopes with very short half lives remain radioactive for fractions of seconds
5
Q
What are some medical uses for radioactivity?
A
Radiotherapy
Radio-imaging
Sterilising medical instruments
6
Q
What are some non medical uses for radioactivity?
A
Checking metal welds
Carbon dating
Smoke alarms
