| 8. 3 | Ionising and Non-ionising Radiation |
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Ionising radiation |
Non-ionising radiation |
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- Ionising radiation contains a higher energy content and causes electrons to be released from the atoms or molecules it irradiates - Examples of ionising radiation are alpha radiation, beta radiation, and gamma radiation |
- Non-ionising radiation has a lower energy content and cannot release electrons from the atoms or molecules it illuminates - Examples of non-ionising radiation are radio waves, microwaves, and infrared |
The characteristics of alpha, beta, and gamma rays:
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Characteristics |
Alpha (α) |
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Particle size |
Big |
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Charge |
Positive |
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Ionising power |
High |
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Penetrating power |
Low |
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Deflection by magnetic fields |
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Deflection by an electric field |
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Beta (β) |
Gamma (γ) |
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Small |
None |
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Negative |
Neutral |
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Medium |
Low |
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Medium |
High |
Sources of ionising radiation:
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Sources of ionising radiation are divided into natural sources and man-made sources
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Sources of natural ionising radiation include cosmic radiation and background radiation
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Cosmic radiation is radiation emitted continuously from outer space that can cause interference with weather and communication systems
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Background radiation is radiation that is present everywhere but the level varies due to solar radiation and the presence of radon-222 gas (radioactive gas in the air)
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Measured in microSievert units/hour (µSv/h)
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Nuclear test and nuclear accident at Chernobyl April 1986 is a source of man-made ionising radiation
Exposure to ionising radiation and safety measures:
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Radioactive effects |
Security measures |
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- Destruction of cells or tissues in the body - Genetic mutations that may cause tumor growth and cancer - Infertility - The skin burns and becomes blind - Limb deformity and death for severe cases |
- Chopsticks should be used to hold and transfer radioactive sources - Radioactive material should be stored in lead containers - Workers in radioactive laboratories must wear radioactive warning badges and special protective clothing made of lead rubber - Lead shields can be used to protect users from radioactive radiation - Radioactive waste must be handled properly so that it is safer and does not cause environmental pollution |
