4 The strong nuclear force Explain why a strong force is 3.2.1.2 The strong nuclear force; MS 0.1 Recognise and use unit 2.3 needed in the nuclear model its role in keeping the nucleus prefixes for small and large Students look at the stable; short-range attraction up distance measurements properties of the strong Describe the way the force to approximately 3 fm, nuclear force in relation to between two protons changes PS 3.1 Interpret the graph repulsion closer than the electrostatic force. as they are brought closer depicting the range and sign of approximately 0.5 fm together the strong nuclear force compared to the electrostatic Interpret force–distance graphs force for the nuclear and electrostatic forces in relation to nucleon separation 5 The neutron and isotopes Understand the reasons for the 3.2.1.1 Simple model of the atom, 2.3 late discovery of the neutron including the proton, neutron and The discovery of the neutron electron and ways to represent the Know what is meant by an Charge and mass of the proton, properties of nucleons are isotope neutron and electron in SI units considered. Interpret and use standard and relative units nuclide notation Specific charge of the proton and the electron, and of nuclei and ions Proton number Z, nucleon number A, nuclide notation Students should be familiar with the notation Meaning of isotopes and the use of isotopic data 6 Radioactivity, alpha Explain that radioactivity is a 3.2.1.2 Unstable nuclei; alpha and ATl Demonstration of the range of 2.4 particles and detectors result of the decay of unstable beta decay alpha particles using a cloud nuclei chamber, spark counter or Geiger Students see demonstrations counter of how radioactivity can be Understand that unstable nuclei detected. may emit alpha particles, producing nuclei of greater stability Know the meaning of ionisation
4 The strong nuclear force Students look at the properties of the strong nuclear force in relation to the electrostatic force. Explain why a strong force is needed in the nuclear model Describe the way the force between two protons changes as they are brought closer together Interpret force–distance graphs for the nuclear and electrostatic forces in relation to nucleon separation 3.2.1.2 The strong nuclear force; its role in keeping the nucleus stable; short-range attraction up to approximately 3 fm, repulsion closer than approximately 0.5 fm MS 0.1 Recognise and use unit prefixes for small and large distance measurements PS 3.1 Interpret the graph depicting the range and sign of the strong nuclear force compared to the electrostatic force 2.3 5 The neutron and isotopes The discovery of the neutron and ways to represent the properties of nucleons are considered. Understand the reasons for the late discovery of the neutron Know what is meant by an isotope Interpret and use standard nuclide notation 3.2.1.1 Simple model of the atom, including the proton, neutron and electron Charge and mass of the proton, neutron and electron in SI units and relative units Specific charge of the proton and the electron, and of nuclei and ions Proton number Z, nucleon number A, nuclide notation Students should be familiar with the notation Meaning of isotopes and the use of isotopic data 2.3 6 Radioactivity, alpha particles and detectors Students see demonstrations of how radioactivity can be detected. Explain that radioactivity is a result of the decay of unstable nuclei Understand that unstable nuclei may emit alpha particles, producing nuclei of greater stability Know the meaning of ionisation 3.2.1.2 Unstable nuclei; alpha and beta decay ATl Demonstration of the range of alpha particles using a cloud chamber, spark counter or Geiger counter 2.4