Answer to Question #176225 in General Chemistry for Paul Warren Dickison

Question

If solar radiation is 1130 W/m

2

W/m2 , how many photons strike the leaf every second? Assume three significant figures and an average wavelength of 504 nm

nm for solar radiation.

Express your answer using three significant figures.

Answer 1

In determining number of photons emitted per second, we need data on the to entire power of the system and the total energy of the photons. It is inevitable determining the power through multiplying the total area to the intensity of the sunlight given. However, the area is not given so we just utilize the power which would be in terms of power per unit area We do as follows:

Power = 1130 W / m^2 

The energy of the visible light

Energy = hc / wavelength

where h is the planck's constant and c is the speed of light

Energy = (6.63 x 10^-34) (3 x 10^8) / 504 x 10^-9

Energy = 3.95 x 10^-19 J

Number of photons per second = 1130 J/s-m^2 / 3.95 x 10^-19 J

Number of photons per second = 2.86 × 10^21 photon per m^2