Question

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 ?

Answer 1

If wavelength is `lambda=1 cm=0.01m`
Frequency is: `nu=c/lambda=(3xx10^8)/0.01=3xx10^10Hz`

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

(Where `c` is the speed of light and `h` is Plank's Constant)

Now using `N_A=6.022xx10^23 mol^-1` you can find the energy you need!