aqa a level physics paper 1 Questions & Answers(Graded A+)

aqa a level physics paper 1 Questions & Answers(Graded A+)What is meant by work function (2) - ANSWERMinimum energy required by an electron to escape from (1) a metal surface (1) What is meant by ionisation energy? (2) - ANSWERMinimum energy required to remove an electron from an atom (1) from the ground state (1) Why do emitted electrons have a kinetic energy that varies up to a maximum value? (4) - ANSWEREnergy of a photon is fixed/constant (1) Energy is required for electrons to overcome work function ø (1) Electrons deeper into/below the surface of the metal require more energy to overcome work function and therefore have less KE(1) Maximum KE = Energy of photon - work function ø (1) Explain how (bright ring) diagram is evidence of the wave-particle duality of electrons? - ANSWERDiffraction pattern maxima/minima (bright and dark areas) (1) Diffraction is a property of waves- proves wave-behaviour of electrons (1)