Molecules Flashcards
1
Q
How molecules exert pressure on inside of container
A
- Molecules exert a force
- when collide with walls of container
- force acting on surface area results in pressure
2
Q
Process of nuclear fission
A
- neutrons captured / absorbed l, causes break up of nucleus / daughter nuclei, releasing energy and neutrons
- spare neutrons cause further fissions - chain reaction
- moderator to slow down neutrons and increase rate
- control rod absorbs neutrons reduces rate - can be inserted and removed
- energy released to heat water
3
Q
What material can control rods be made from
A
Boron
4
Q
Material for fuel rod
A
Uranium
5
Q
Material for moderator
A
Graphite
6
Q
Material for outer shield
A
Steel
7
Q
Which part in which nuclear fission takes place
A
Fuel rid
8
Q
Problems of disposal of waste from nuclear power station
A
- emits radiation, high activity
- long half life
- harmful to people and environment
- expensive to contain
- shielding - need for security
9
Q
How can radioactivity be used estimate age of archaeological discoveries
A
- living things contain carbon - 14
- C14 is radioactive isotope - beta emitter
- radioactivity decreases over time
- estimate half lives since material was alive
- compare activity of sample with now living tissue
- ratio of C12 to C14 is fixed in living material
10
Q
Role of moderator
A
- slows down neutrons
* encourage fission - more efficient reaction
11
Q
Role of control rods
A
Control rate of reaction
Absorb neutrons
