Question

How many photons of light with a wavelength of 400 pico metere are necessary to provide 1 joule of energy ​

Answer 1

the number of photons with a wavelength of 4000 pm and energy of 1 J are 2.012 * 10^16.

Answer 2

Answer:

Energy of one photon =hv=h⋅λc

                                    =4000×10−10(6.62×10−34)(3.0×108)

                                    =4.965×10−19J

Number of photons =4.965×10−191.00=2.01×1018

Hence, 2.01×1018 photons of light having a wavelength 4000A˚ are necessary to provide 1.00J of energy