X-rays in space

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Atoms
The atom comprises three particles:
electrons (-), protons (+) and neutrons.
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• energy that is given out by atoms at high speed is called radiation – two main forms; electromagnetic radiation and atomic particles.
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neutron – strikes the nucleus and is absorbed.

incident neutron – the nucleus absorbed causes the nucleus to undergo deformation. In around 10-14 seconds, one of the deformations is so drastic that the nucleus cannot recover.

splitting of nucleus – the nucleus fissions, releasing an average of two to three neutrons.

fission nucleus – in around 10-12 seconds, the fission fragments lose their kinetic energy and come to rest, emitting a number of gamma rays. Now the fragments are called fission products.

incident neutrons – the fission products lose their excess energy by radioactive decay, emitting particles over a lengthy time period (seconds to years).

other more fission product – the course of a chain reaction is determined by the probability that a neutron released in fission will cause a subsequent fission.

Nuclear Power Plant

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• nuclear fission takes place inside the reactor of a nuclear power plant.
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• nuclear power plants heat water to produce steam.
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• nuclear power plants use heat produced during nuclear fission to heat water.
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Atoms
The atom comprises three particles:
electrons (-), protons (+) and neutrons.

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• every star in the universe – it can be released either by nuclear fusion or nuclear fission.
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• the energy that holds the nucleus of every atom together is called nuclear energy.
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• nuclear energy fuels nuclear power stations, and every star in the universe – it can be released either by fission or fusion.
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• energy that is given out by atoms at high speed is called radiation – two main forms; electromagnetic radiation and atomic particles.
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• nuclei – usually only tiny nuclei, such as those of hydrogen and helium, fuse (join); only under extreme pressure in huge, exploding stars do big nuclei – such as those of iron.
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• nuclear fission – it happens when nuclear energy is released by the splitting of nuclei; this method used in most power stations and in atomic bombs – involves splitting big nuclei; such as Uranium-235 and plutonium.
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• when a nucleus splits, it gives out gamma rays, neutrons (see atom) and intense heat.
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• in an atomic bomb – the energy is released in one second!
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• in a power station – control rods ensure that nuclear reactions are slowed down to release energy gradually.
  
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mankind: Hiroshima bomb at Japan – released 84 trillion joules of energy.

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