AQA AS Physics Definitions Exam Questions and Answers 100% Pass

AQA AS Physics Definitions Exam Questions and Answers 100% Pass Specific charge the charge to mass ratio or charge in coulombs divided by the mass in kilograms Isotope a nucleus with the same number of protons but different number of neutrons Hadron a particle that experiences the strong nuclear force. Composite particles made of either qqq (baryons) or q anti-q (baryon) Antimatter Particles with the same mass but opposite charge Photoelectric effect the emission of electrons from metal surfaces by light of an appropriate frequency Photon a discrete packet/quantum of electromagnetic energy Work function the minimum energy required for an electron to escape from the surface of the metal Threshold frequency the minimum frequency of a photon required to release electrons from the surface of a metal Electron volt the energy given to an electron when it passes through a potential difference of 1 V Energy Level Allowed/discrete energy of an atom or electron in an atom Ionisation energy of an atom the minimum energy required to remove an electron from an atom in its ground state Excitation energy the energy required to move an electron from a lower energy level to a higher energy level Line spectra the characteristic wavelengths of light produced by individual excited atoms