Microwave radiation has a wavelength on the order of 1.0 cm. Calculate the frequency and the energy of a single photon of this radiation. How to calculate the energy of an Avogadro’s number of photons (called an einstein) of this radiation ?

1 Answer
Apr 8, 2015

If wavelength is lambda=1 cm=0.01mλ=1cm=0.01m
Frequency is: nu=c/lambda=(3xx10^8)/0.01=3xx10^10Hzν=cλ=3×1080.01=3×1010Hz

Energy of one photon of this frequency will be (From Einstein's relationship):
E=h*nu=6.63xx10^(-34)*3xx10^10~=2xx10^-23JE=hν=6.63×10343×10102×1023J

(Where cc is the speed of light and hh is Plank's Constant)

Now using N_A=6.022xx10^23 mol^-1NA=6.022×1023mol1 you can find the energy you need!