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P6: Radioactivity

P6.1 Radioactive emissions

P6.1a recall that atomic nuclei are composed of both protons and neutrons, that the nucleus of each element has a characteristic positive charge

P6.1b recall that atoms of the same elements can differ in nuclear mass by having different numbers of neutrons

P6.1c use the conventional representation for nuclei to relate the differences between isotopes to include identities, charges and masses

P6.1d recall that some nuclei are unstable and may emit alpha particles, beta particles, or neutrons, and electromagnetic radiation as gamma rays

P6.1e relate these emissions to possible changes in the mass or the charge of the nucleus, or both

P6.1f use names and symbols of common nuclei and particles to write balanced equations that represent radioactive decay

P6.1g balance equations representing the emission of alpha-, beta- or gamma-radiations in terms of the masses, and charges of the atoms involved (M1b, M1c, M3c)

P6.1h recall that in each atom its electrons are arranged at different distances from the nucleus, that such arrangements may change with absorption or emission of electromagnetic radiation and that atoms can become ions by loss of outer electrons

P6.1i recall that changes in atoms and nuclei can also generate and absorb radiations over a wide frequency range (to include an understanding that these types of radiation may be from any part of the electromagnetic spectrum which includes gamma rays)

P6.1j explain the concept of half-life and how this is related to the random nature of radioactive decay

P6.1k calculate the net decline, expressed as a ratio, during radioactive emission after a given (integral) number of half-lives (M1c, M3d)

P6.1l recall the differences in the penetration properties of alpha-particles, beta-particles and gamma-rays

 P6.2 Uses and hazards

P6.2a recall the differences between contamination and irradiation effects and compare the hazards associated with these two

P6.2b explain why the hazards associated with radioactive material differ according to the half-life involved

P6.2c describe the different uses of nuclear radiations for exploration of internal organs, and for control or destruction of unwanted tissue

P6.2d recall that some nuclei are unstable and may split, and relate such effects to radiation which might emerge, to transfer of energy to other particles and to the possibility of chain reactions

P6.2e describe the process of nuclear fusion