Alpha Beta Gamma
Jan 26, 2016
AlphaBeta
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AlphaBeta
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Lesson ContentsLesson Contents1. Physical properties of ,
and 2. Penetrating power
of,and3. N v Zgraphs4. Decay laws
Alpha RadiationAlpha RadiationAlpha particles contain two protons and two neutrons
Alpha RadiationAlpha Radiation has the same constitution as a helium nucleusAlpha particles may be written as
They have a double positive charge and a mass of 4 u
Beta-minus RadiationBeta-minus RadiationBeta-minus particles are electrons
Beta-minus RadiationBeta-minus Radiation- is produced when a neutron decaysBeta-minus particles may be written as
They have a negative charge and a mass of 1/1800 u
Beta-minus RadiationBeta-minus Radiation
- is produced when a neutron decays
The surplus mass is released as kinetic energy in the - and as an antineutrino
Gamma RadiationGamma RadiationGamma rays are a form of electro-magnetic radiation
Gamma RadiationGamma Radiation release is often associated with or decayGamma rays remove energy from an unstable nucleus
Beta-plus RadiationBeta-plus Radiation+ particles are positrons
Beta-plus RadiationBeta-plus Radiation+ is produced when a proton decays
The surplus mass is released as kinetic energy in the + and as a neutrino
Penetrating powerPenetrating power has a high massIt is stopped by a few centimetres of air has a small massIt is stopped by a few millimetres of aluminium has zero massIt is stopped by thick lead or concrete
Penetrating powerPenetrating power has a high chargeIt is dangerous if swallowed
has a small chargeIt is dangerous at medium range has high energyIt is dangerous at distance
Penetrating powerPenetrating power
N v Z graphsN v Z graphsA Graph of neutron number (N) against proton number (Z) helps to predict whether an isotope will emit or -
radiation
N v Z graphsN v Z graphsIsotopes in this region emit particles to become more stable.N decreases by 2Z decreases by 2
N v Z graphsN v Z graphsIsotopes in this region emit particles to become more stable.N decreases by 1Z increases by 1
Decay laws - alphaDecay laws - alphaWhen an isotope emits an particle Its nucleon number decreases by 4 Its proton number decreases by 2For example:
Decay laws – beta-minus
Decay laws – beta-minus
When an isotope emits a- particle Its nucleon number is unchanged Its proton number increases by 1For example:
Decay laws – beta-plus
Decay laws – beta-plus
When an isotope emits a+ particle Its nucleon number is unchanged Its proton number decreases by 1For example:
Decay lawsDecay lawsTry writing the nuclear equations for the decay of these isotopes
Decay lawsDecay lawsAnswers
AlphaBeta
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AlphaBeta
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