Topic 7 Flashcards
How can electricity be generated from nuclear fission in nuclear power stations
Fuel rods containing uranium undergo nuclear fission
Thermal released
Thermal energy from nuclear sodium is taken by the coolant to heat water to produce steam
The steam causes turnings to rotate which turns the generator to generate electricity
The steam is cooled back into water in a condenser so it can be used again
Extra thermal energy is released from cooling towers or intoxthe sea
Generating electrical energy from nuclear fission
It is the thermal energy from nuclear fission that is most useful for the generation of electricity in a power station
A coolant such as water is pumped through the reactor
Explain how the contour rods work in a nuclear power station
The control rods absorbs neutrons if the control rods are pushed down into the core more neutrons are absorbed and the chain reaction slows down if they are pulled out then fewer neutrons are absorbed and the chain reaction speeds up
What does nuclear fusion involve
The joining of smaller nuclei to form larger nuclei.
Obtaining a continuous supply of energy from nuclear fusion is more difficult than obtaining energy from nuclear fission
Nuclear fusion
Happens when a small nuclei join to from larger ones
Like all nuclear reactions fusion reactions release energy
Fusion and starts
During the stable period of a stars life vast quantities of hydrogen nuclei are converted to helium nuclei by nuclear fusion. This is the source of energy for starts
Over time heavier elements are formed and the star will eventually die. This will take our sun billions of years.
The mass of the products is slightly less than the mass of the reactants- this mass difference is released as energy in the form of thermal energy
This reaction takes place under very high pressure and temperature in stars
One of the typical reactions that takes place in the sun
2H + 3H -> 4He + 1n + energy
1 1 2 0
Difficulties of fusion
Nuclei need to get very close together before this can happen
Under normal conditions the positive charges on nuclei repel each other
= electrostatic repulsion
Only a very Hugh temp and pressures are the nuclei moving fast enough to overcome this electrostatic repulsion
The very Hugh temps and pressures needed are very difficult to produce in a fusion power station. All the experimental fusion reactors built so far have used more energy than they have produced
Explain the difference between nuclear fusion and nuclear fission
In nuclear fission hydrogen nuclei fuse to produce nuclei whereas in nuclear fission uranium-235
Splits into two smaller nuclei and two or three neutrons
Nuclear fusion requires very Hugh temperatures and pressure whereas nuclear fission requires a slow-moving neutron to be absorbed
Both processes release large quantities of energy
What does the solar system include
Sun Eight planets Natural stallites Dwarf planets Asteroids Comets
Order of plants
Hdisidoc
What do most asteroids do
Form a ring of rocks that orbits the sun and is found between mars and Jupiter
Comets travel in highly elliptical paths and come from
Many millions of miles away
Pluto used to be classed as a plants but was downgraded to a dwarf planet in 2006 due to
It’s small mass and location in space
Earth has one natural satellite called
The moon. Larger planets such as Jupiter and Saturn have many natural satellites or moons
