Quantum

• Photoelectric effect 


  The emission of electrons from a metal when light of high enough frequency is shone on it.
• Threshold frequency 


  The minimum frequency of photons required for photoelectrons to be emitted from the surface of a metal to late through the photoelectric effect. It is equal to the metal‘s work function divided by Planck’s constant.
• Work function 


  The minimum energy required to remove an electron from a metal’s surface.
• Stopping potential 


  The minimum potential difference required to stop the highest kinetic energy electrons from leaving the metal plate in the photoelectric effect.
• Ionisation


  Is Process of an atom losing an orbital electron and becoming charged.
• Excitation


  The process of an electron taking in exactly the right quantity of an energy to move to a higher energy level.
• Electron-volt (eV)


  The work done to accelerate an electron through a potential difference of 1V. 1eV is equal to the charge of an electron (E=qv)
• Energy levels


  Defined and distinct energies at which electrons can exist in an atom. An electron cannot exist between energy levels
• Ground state


  The most stable energy level that an electron can exist exist in
• Ionisation energy 


  The energy required to remove an electron from an atom
• Fluorescence 


  Glow of light from a substance exposed to ultraviolet radiation; the atoms de-excite in stages and emit visible photons in the process.
• Line emission spectrum 


  A spectrum of bright lines of on a dark background corresponding to different wavelengths of light that have been emitted from a source.
• Line absorption spectrum 


  A spectrum with dark lines corresponding to different wavelengths of light that have been absorbed
• De Broglie wavelength


  the wavelength of a matter particle
• Wave-particle duality 


  All particles can be shown to exhibit wave-like properties and waves can be shown to exhibit particle-like properties.
• Electron diffraction


  The spreading of electrons as they pass through a gap similar size to the magnitude of their De Broglie wavelength. It is evidence of the wave-like properties of particles.