- Chinese name
- Particle property
- Foreign name
- Particle (English)
- Definition
- Electromagnetic radiation energy can exist in discrete form in addition to its continuous wave state
- Classification
- Physical terms
People only know that light is a kind of electromagnetic wave When it interacts with charged particles, it shows an energy and momentum Discontinuity (usually called particle property) 1. Photoelectric effect
⑴ The phenomenon that an object emits electrons under the irradiation of light is called photoelectric effect . (2) Einstein's Photon theory Light is discontinuous. It is divided into several parts. Each part is called a photon , photon energy E and light frequency ν Proportional: E=h ν (3) The rule of photoelectric effect:
All kinds of metals exist Limiting frequency ν 0, only ν≥ν 0 can produce photoelectric effect; Instantaneous (photoelectron generation shall not exceed 10-9s)
③ Light electric Maximum initial of a child kinetic energy And incident light The intensity is independent of the incident light frequency, and only increases with the increase of the incident light frequency; ④ When the frequency of the incident light is greater than the limit frequency, the intensity of the photocurrent is proportional to the intensity of the incident light
(4) Einstein Photoelectric effect equation :Ek= h ν - W (Ek=1/2mv ^ 2, is the maximum initial kinetic energy of photoelectron; h ν Is the energy of photon, W is Escape work That is, photoelectrons flying directly from the metal surface overcome positive charge Work done by gravity.) For Einstein Photoelectric effect equation EK= h ν- W. The following understandings are correct A. As long as the same metal is irradiated by light of the same frequency, all photoelectrons escaping from the metal will have the same initial kinetic energy EK
B. In the formula, W represents the work done by each photoelectron to overcome the positive charge gravity in the metal when flying out of the metal
C. Escape work W and Limiting frequency ν The relationship between 0 should meet the equation W=h ν zero D. Maximum initial of photoelectron kinetic energy Is proportional to the frequency of the incident light Solution: Einstein photoelectric effect equation EK=h ν- W in W represents the work done by photoelectrons escaping directly from the metal surface to overcome the gravity of positive charges in the metal, so it is the minimum work done by all escaped photoelectrons to overcome the gravity. The corresponding initial kinetic energy of photoelectrons is the largest among all photoelectrons. The initial kinetic energy of other photoelectrons is less than this value. If the frequency of incident light is just the limit frequency, that is, photoelectrons can just escape, It can be understood that the maximum initial kinetic energy of the escaped photoelectron is 0, so W=h ν 0. By EK=h ν- W Know EK and ν Between Linear function Relationship, but not in direct proportion. This question should choose C 
