Question

What is the energy (in electron volts) of a 110 GHz (1 gigahertz = 109 Hz ) microwave photon?

Express your answer using two significant figures.
E = ______ eV

Answer 1

Use the frequency and Planck's constant to find the energy as shown below:

E = h x f
E = (6.626 x 10^-34 Js) x (110 x 10^9 Hz) / (1.6 x 10^-19)
E = (7.2886 x 10^-23 J) / (1.6 x 10^-19) eV
E = 0.0004555375 eV
E = 4.6 x 10^-4 eV