Fission and Fusion Flashcards
nuclear fusion
the process of combining light nuclei to form a heavier nucleus
when stars fuse hydrogen
heavier atoms and vast amounts of energy are created
when a star runs out of hydrogen… and helium… what happens?
it starts to fuse other things together to make other elements & even heavier elements until it:
1. runs out of fuel
2. goes cold
3. gets so dense that the pressure inside blows it apart (nova or supernova)
what happens to the various atoms inside the stars after it runs out of hydrogen and helium?
they scatter into the cosmos to eventually collect to make more stars and also planets
without fusion life would be
impossible
nuclear fission
splitting of a nucleus into 2 smaller nuclei; usually involves a neutron hitting a large, unstable nucleus just right
tiny bit of mass was converted into a huge amount of energy
e = mc^2
c = speed of light =
3 x 10^8m/s
nuclear
2 x 10^13 J per mole ^235U
_ of the world’s energy comes from nuclear power.
_ of the US’s energy comes from nuclear power
17%
20%
currently there are about _ nuclear power plants in the US and about _ worldwide
100
500
dangers of radiation exposure
- cosmic rays
- ground and surroundings
- human body
- medical and dental x rays
- air travel
- fallout from weapons test
- nuclear waste
1 mrem
1 millirem = 1 x 10 ^-3 rem
dose (mrem/yr) of medical and dental x rays
50-75
dose of cosmic rays
20 -50 mrem/yr
