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Atomic Structure 2, image, image - Coggle Diagram
Atomic Structure 2
Half life
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Each time a radioactive nucleus decays to become a stable nucleus the activity as a whole will decrease
A short half life means that the activity falls quickly because the nuclei are very unstable and rapidly decay
A long half life means the activity falls more slowly as most the nuclei don't decay for a long time, the source just sits their, releasing small amounts of radiation for a long time
Uses and risk
risk
Radiation sources can enter living cells and ionise atoms and molecules within them. This can lead to tissue damage
Lower doses tend to cause minor damage without killing the cells. This can give rise to mutant cells which divide uncontrollably - cancer.
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uses
Gamma sources are used in medical tracers because they pass through the body without much ionisation. Short half life to disappear quickly
Also used in radiotherapy, gamma rays are directed with right dosage to kill cancer cells without killing too many normal cells
Fission and fusion
Fission
Nuclear fission is a type of nuclear reaction that is used to release energy from large and unstable atoms by splitting them into smaller atoms
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2) When an atom splits, it forms two new lighter elements that are roughly the same size
3) Two or three neutrons are also released when the atom splits. If any of these neutrons are moving slow enough to be absorbed by another nucleus they can cause more fission to occur. Chain.
5) The energy not transferred to the kinetic energy stores of the products is carried away by gamma rays
4) The energy not transferred to the kinetic energy stores of the products is carried away by gamma rays
6) The amount of energy produced by fission in a nuclear reactor is controlled by changing how quickly the chain reaction can occur. Control rods do this by lowering and raising inside a nuclear reactor to absorb neutrons to slow down the chain reaction and control the amount of energy released.
7) Uncontrolled chain reactions quickly lead to lots of energy being released as an explosion - this is how nuclear weapons work.
Fusion
Two light nuclei collide to create a larger heavier nucleus but some energy is released in the process
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Temperature an pressure needed for fusion are so high that fusion reactors are hard and expensive to build
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