How Many Photons Are Emitted Based on Intensity and Photon Energy?

AI Thread Summary
The discussion centers on calculating the number of photons emitted based on electromagnetic intensity and photon energy. The classical definition of intensity is given as energy per time per surface area squared. To determine the number of photons emitted at a specific intensity, one must consider the frequency of the photons. Using Planck's relationship, the energy of a single photon can be calculated, and dividing the total power by this energy yields the number of photons per unit area per second. Understanding this relationship is crucial for accurate photon emission calculations.
Nopollution
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Dear all,

I have the next question: if we consider the classical definition of electromagnetic intensity it is given by [energy]/[time x surface^2]. At the same time intensity is related to the number of photons of the em radiation. So my question: given for example an intensity of 5W/[sec x cm^2] at energy Ep, how many photons at the same energy are emitted?

Thanks,
Nop
 
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Depends on the frequency of the photons. Planck's relationship will give you the energy of a single photon, divide the power by the energy of a single photon to obtain the number of photons passing through the unit area per second.
 

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