P2.6 Nuclear fission/fusion Flashcards
How can nuclear fission be used to generate electricity?
The nuclei split and release energy which can heat water into steam, drive a turbine, and power a generator to generate electricity
What happens during the process of nuclear fission?
Nuclei split, releasing energy
How is energy released in stars?
Through nuclear fusion
Nuclear fission is where atomic nuclei…
…split
What happens to the energy released at each stage of nuclear fusion?
Carried away as kinetic energy of the product nucleus
Give 2 disadvantages of fission reactors
Uranium is hard to find and is only in certain parts of the world.
They produce nuclear waste that needs to be stored securely
What substances are used in nuclear fission reactors?
Uranium-235
Plutonium-239
For fission to occur, the Uranium-235 or Plutonium-239 nucleus…
…must absorb a neutron
What happens when a nucleus undergoes fission?
Splits, two smaller nuclei
Releases 2 or 3 neutrons (fission neutrons)
Releases energy in the form of radiation
When do stars form?
When enough dust and gas from space is pulled together
What force pulls dust and gases together to make stars?
Gravitational attraction
Where and when does a chain reaction occur? (Fission)
It occurs in a nuclear reactor when each fission event causes further fission events
How is a chain reaction in a nuclear reactor controlled? (Fission)
Control rods absorb surplus neutrons so that on average only one neutron per fission goes on to produce further fission
(BLACK HOLE FORMATION)
A ___bigger than the ___ becomes a ___ and___ . The outer layers are ___into___and the ___is left as a dense___. If it is massive enough it will form a___ which has a____so___that ___can’t escape
A STAR bigger than the SUN becomes a SUPERNOVA and EXPLODES. The outer layers are THROWN into SPACE and the CORE is left as a dense NEUTRON STAR. If it is massive enough it will form a BLACK HOLE which has a GRAVITATIONAL ATTRACTION so strong that LIGHT can’t escape
When are elements heavier than iron formed? Why at that time only?
In a supernova; the process requires the input of energy
