how can u demonstrate the photoelectric effect?
411386
photoelectric effect can be demostrated if u can excite an electron in a material so that it has enough energy to leave the matrial. i.e. E > (Evacuum-Ef). now u need to look at the energy of the free electron which can be found simply by putiing in through a magnetic field. the deflection will depend on the velocity and hence its energy. this excitation of the electron is done by electromagnetic radiation or light. this free electron is actually free and is not as that meant in semiconductors where free means that it is STILL in the material but free to move. moreover the "free" electron in a semiconductor, even if excited to a higher energy than the conduction band edge, will come down to the conduction band edge by various non-radiative process and than move. photoelectric effect can also be seen in semiconductors if the excitation is so high such that the electron leaves the material. this method is used to find the position of the fermi level.
753808
Do demonstrate the electric current produced by the acids reacting with the probes.  Your lemon is really a battery.
531368
Electrons.\nPhotons.\nHeat.
875072
Here's an interesting experiment.
924231
use a photo transistor that is triggered by the light emitted from the LED to click some relays or something.
1031895
Quite simple really. All you need is a photodiode detector sensitive in the infrared region and a computer or oscilloscope to measure the voltage difference of your photodiode detector.\n\nYour homebrew device is useful, but only as useful as the components it is constructed of. Lab quality devices cost tens of thousands of dollars and have well conditioned electronics.
515931
If you stick two electrodes with a light bulb into salty water, the light will shine brightly, showing that it really is a good conductor of electricity. The more ions you add, the more brightly the light will shine.\n\nSo in other words, it sure is a good conductor and it is one because of the NaCl-  (Sodium chloride) in it.
108122
http://science.howstuffworks.com/lightning.htm
965176
http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/light/u12l1e.html
31683
simply : The sudden emission of electrons from the surface of metal when a light of certain frequency falls on its surface.\n\natomic view :when light of frequency greater than the threshold frequency of metal falls which have low work function, electrons are emitted from their surfaces. The emitted electrons are called photoelectrons and the phenomena is called photoelectric effect.suitable material for photo electric effect 'selenium'.\nThree major features of the photoelectric effect that cannot be explained on the basis of classical wave theory of light.\n1- Intensity problem: number of emitted electrons increased by increasing the intensity of incident light.\n2-Frequency problem: effect should start at any frequency of incident light, provided only that the light is intense enough to supply the energy needed to eject the photoelectrons.\n3-Time delay problem: there is a time lag between the impinging of the light on the surface and the ejection of electrons, as they must aquire sufficient energy to eject.\nlater on the Einstien's Photon theory solved these problems i.e. E=hv\nwhere 'v' is the frequency of incident light. equation shows light beam behaves like a stream of paritcles called photons each having energy 'hv'.\nEinstien's theory solved the prolems i.e. no matter how much the intensity of incident light but depends on the frequency of incident light called the threshold frequency. Effect starts at once if frequecy is greater and no detectable time lag has ever been recorded.
353533
If you could find a transition between an inverted state and a ground state of 1 joule, you could probably make a laser of that frequency. At this point, hard gamma rays are the limit we have done.
1166742
solar cells produce electricity through a process known as photoelectricity.Photoelectricity means a process in which light is shone (fall on) photocells which bring about the release of electrons.i.e.production of electricity .
831271
Dear Madame,\n\nYou could try testing wave-particle duality nature of photons, and report on how the theory corresponds with Schodiger's findings in the early 20th century. \n\nAnyone can put a light bulb in a potato. Also, the above response about commercials is about as unscientific as you can get. I don't trust emus.\n\nPianoguy
1163833
reflected light will dominate the picture so you meter the most effect
576638
La detectacion de luz ,como photon o como onda, depende del typo o metodo de experimento para explorar la naturaleza de la luz. La luz exhibe la characteristica de honda en experimentos de diffraccion e interferencia y exhibe characteristicas de particula en experimentos de ionizacion de atomos con radiacion de varias energias. La luz se mueve en linea recta a menos que es reflejada o desviada por el medio atraves cual viaja. La luz que proviene de estrellas y galaxias distantes provee informacion soble la velocidad de esas estrellas y galaxias porque la luz como onda es cambiada como es cambiado el sonido de un tren qhe primero se aproxima y despues se aleja. ( vea terminos como "red-shift" and "doppler effect") El sonido aumenta cuando el tren viene y despues mengua cuando el tren se va.
438026
(m)\n\nPhotoconductivity is the tendency of a substance to conduct electricity to an extent that depends on the intensity of light-radiant energy (usually infrared transmission or visible light) striking the surface of a sample. Most semiconductor materials have this property.\n\nWhen there is no illumination, a photoconductive sample has a conductance that depends on its dimensions, on the specific material(s) from which it is made, and on the temperature. In most cases, the greater the radiant energy of a specific wavelength that strikes the surface, the higher the conductance of the sample becomes, up to a certain maximum. When the maximum conductance is reached for a particular sample, further increases in irradiation produce no change in the conductance.\n\nPhotoconductive materials are used in the manufacture of photoelectric devices. Typical photoconductive substances consist of germanium, gallium, selenium, or silicon with impurities, also known as dopants, added. Other common materials include metal oxides and sulfides
601580
Yeah man...light is one of the most energetic forms that we witness. Light actually has many types of energy, just like most other things. \n\n1) Photons of light (of a suitable frequency are capable of imparting enough momentum to an electron in a metal so that the electron leaves the metal's surface. This is known as the photoelectric effect and the credit for it's knowledge goes to Mr.Einstein.\n\n2) Light has heat energy, and therefore thermodynamic value. You'll see that if you stand in the sun too long, you will be hot. \n\n3) The thermodynamic energy of light causes photochemical reactions, such as the radicalisation of halogen atoms, or the redox reactions of alkyl halides. \n\nI cannot be too sure of my satisfaction quotient with this answer because your question overlays so many fundamental concepts of light. For example, you wouldn't ask a rolling ball, "Excuse me sir, but how much energy do you really have?" The ball will snicker because you have not specified WHAT KIND OF ENERGY you want from the ball. Now, if you were to ask, "Excuse me sir, what is your KINETIC energy?", the ball would happily answer that it would be half of its mass multiplied by the square of its velocity. \n\nOne of the kinds of energy does involve a mass parameter and that would be the photoelectrical energy of light. This energy functions on the sound premise that linear and angular momentum are conserved, and since light has dual (mass-wave) nature, this kind of energy does involve mass. \n\nWe know that the energy of a photon of frequency v is E=hv where h is Planck's constant. We also know that the energy of a photon in relation to its mass is E=mc^2. THus we can say:\n\nmc^2 = hv.\n\nAll right, here is a clear answer, which I just realized. \n\nOne photon of light has the above mentioned amount of energy, and therefore a ray of light will have the energy of how many ever photons are in the ray of light. \n\nSo for n photons, energy of the ray of light is nhv. \n\nNow THIS nhv can be CONVERTED into all of the forms mentioned above. Light has energy which is capable of doing different kinds of work. \n\nForgive me for the error of thinking that light has different forms of energy. It has one form of energy which can be CONVERTED into different forms of energy. Phew....\n\nI really must thank you as this was a learning process for me too.\n\nAyerhs.