Lénard did an experiment proving that this was not true. Einstein explained that different particles of light or photons have different frequencies. Therefore, increasing the intensity of low frequency photons has no effect, while using a higher (blue or ultra violet) frequency of light does cause more electrons to be emitted. The formula Einstein used to explain this was e = hf, where h is Planck's constant and f is the frequency.[http://www.physlink.com/Education/AskExperts/ae24.cfm?CFID=8792067&CFTOKEN=36662276] | Lénard did an experiment proving that this was not true. Einstein explained that different particles of light or photons have different frequencies. Therefore, increasing the intensity of low frequency photons has no effect, while using a higher (blue or ultra violet) frequency of light does cause more electrons to be emitted. The formula Einstein used to explain this was e = hf, where h is Planck's constant and f is the frequency.[http://www.physlink.com/Education/AskExperts/ae24.cfm?CFID=8792067&CFTOKEN=36662276] |