Topic 4 Fission And Fusion Flashcards
What is nuclear fission
A type of nuclear reaction that release energy from large unstable atoms by splitting them into smaller atoms
How often does spontaneous fission happen
Rarely as usually the nucleus has to absorb a neutron before it will split
What does the atom form when it splits by nuclear fission
Two new and lighter elements that are roughly the same size (and have some kinetic energy in there stores)
What can be released when the atoms splits
2 or 3 neutrons
What are the neutrons released for
To be absorbed by another nucleus and can cause more fission to occur in a chain reaction
What happens to the energy that isn’t transferred to kinetic energy stores in fission
Carried away by gamma rays
What can be used to spin turbine and generators from fission
The energy carried by gamma rays and in the kinetic stones of the remaining free neutrons and other decay products can be use to heat water and make steam
What is the amount of energy produced by fission in a nuclear reaction controlled by
How quickly the chain reaction can occur
What is done to control the amount of energy released by fission
Control rods which are lowered and raised inside nuclear reactor to absorb neutrons and slow down the chain of reaction which controls the amount of energy being released
What causes explosions and nuclear weapons
Uncontrolled chain reactions happen quickly and lead to lots of energy being released and causes an explosion
What is nuclear fusion
Opposite of nuclear fission
Two light nuclei collide at high speed and join(fuse) to create larger heavier nucleus
E.g hydrogen nuclei fuse to produce a helium nucleus
Why is the larger nucleus made in nuclear fusion not as heavy as the two separate nuclei
Because some of the lighter nuclei is converted to energy and released
Does fusion release more energy than fission
Yes
Why haven’t scientists found a way of using fusion to create energy for us to use
Because the temperatures and pressures needed for fusion are so high that fusion reactors are really hard and expensive to bulif
What happens in nuclear fusion
Two light nuclei collide at high speed and fuse
