P2.6 (Nuclear Fission + Fusion) Flashcards
What can the main sequence star become depending on it’s size?
A red giant (if it is the same size as the sun)
A super red giant (if it is bigger than the sun)
What process fuses two nuclei together to form a larger one?
NUCLEAR FUSION
What process splits a nucleus into two smaller ones?
NUCLEAR FISSION
self sustaining reaction
What do the control rods do in nuclear fission?
Absorb neutrons and prevent the escalation of a chain reaction.
What safety precautions are in place in nuclear fission to slow the process down?
Water and control rods
Is nuclear fusion or fission a decay process?
Nuclear fission as it is the breaking down of a nucleus
How is nuclear fission self sufficient?
The nucleus release three or four more neutrons which hit other neutrons and start a chain reaction slowed down by water and control rods.
Whta elements are commonly used in nuclear fission?
Uranium 235
Plutonium 239
What is the job of the moderator in a nuclear reactor?
Slows the neutrons down
What will the supernova become if the mass left over is four or more time larger than that of the sun?
A black hole
What is the name of the process by which elements are made in a star?
Nuclear fusion
What process must happen before a star can become a main sequence star?
Nuclear fusion
What is the correct order for life cycle of a star?
Nebulae
red giant
protostar
white dwarf
Nebulae Protostar red giant white dwarf black dwarf
or
super red giant
supernova
black hole / neutron star
What produces more energy?
Nuclear fusion
What is produced by uranium in nuclear fission?
Two daughter nuclei, two or more neutrons, a burst of energy
Why is it difficult to have a nuclear fusion power station?
It is hard to safely maintain the pressure and heat required.
Why is high pressure needed in nuclear fusion?
To overcome the electrostatic repulsion between the protons in the hydrogen isotopes.
