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Published byMelanie Hutchinson Modified over 8 years ago
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Alpha Radiation
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Label the helium atom and fill in the table: P_____ N_____ E_____ { N_____ ParticleMassCharge Proton Neutron Electron eutron lectron roton ucleus 1 1 1/1840th +1 none
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Alpha radiation - Helium nuclei Description: 2 neutrons, 2 protons (helium nuclei) Electric Charge: +2 Relative Atomic Mass: 4 Penetration power: Stopped by paper or a few cm of air Ionisation effect: Strongly ionising Effects of Magnetic/Electric Field: Weakly deflected
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Notation Atomic number: The number of protons (which is the same as number of electrons) in a neutral atom. Mass number: The number of protons plus the number of neutrons in a neutral atom. Element symbol A X Z
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Alpha decay Type of decay: What is emitted? Description of decay: Example of decay: Effect on A and Z: Alpha particle (helium nuclei) 238 234 4 U Th + + energy 92 90 2 2 neutrons and 2 protons are emitted from the nucleus. A decreases by 4, Z decreases by 2 (A-4, Z-2)
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Thin mica Thin aluminium Thick lead Skin or paper stops ALPHA The penetration power of alpha radiation.
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Beta Radiation
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Beta radiation - high energy electron Description: High energy electron Electric Charge: Relative Atomic Mass: 1/1860th Penetration power: Stopped by few mm of aluminium Ionisation effect: Weakly ionising Effects of Magnetic/Electric Field: Strongly deflected
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Beta decay Type of decay: What is emitted? Description of decay: Example of decay: Effect on A and Z: High energy electron 14 14 0 C N + + energy 6 7 -1 A neutron in the nucleus decays into a proton and a high energy electron which is emitted. A stays the same, Z increases by 1 (A=, Z+1)
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Thin mica Thin aluminium stops BETA Thick leadSkin or paper The penetration power of beta radiation.
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Gamma Radiation
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Gamma radiation - Electromagnetic radiation Description: High energy electromagnetic radiation Electric Charge: 0 Relative Atomic Mass: 0 Penetration power: Reduced by several cm’s of lead or several metres of concrete Ionisation effect: Very weakly ionising Effects of Magnetic/Electric Field: NO deflection
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Gamma decay Type of decay: What is emitted? Description of decay: Effect on A and Z: High energy electromagnetic radiation. Nucleus changes shape into a more stable shape. Gamma radiation emitted as a result. A stays the same, Z stays the same
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Thin mica Thin aluminium Thick lead reduces GAMMA Skin or paper The penetration power of gamma radiation.
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Thin mica Thin aluminium stops BETA Thick lead reduces GAMMA Skin or paper stops ALPHA The penetration power of the three types of radiation.
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