Question

question 1 (2 points)
if the energy of a photon of light decreases, the ______________
frequency will decrease and the wavelength will increase
frequency will increase and the wavelength will decrease
frequency will increase and the wavelength will increase
frequency will decrease and the wavelength will decrease

Explanation:

The energy of a photon is given by $E = h
u$, where $h$ is Planck's constant and $
u$ is frequency. So energy is directly proportional to frequency. Also, $c=\lambda
u$ (where $c$ is the speed of light), meaning frequency and wavelength $\lambda$ are inversely - proportional. When energy decreases, frequency decreases due to the $E = h
u$ relationship. Since frequency and wavelength are inversely - proportional, when frequency decreases, wavelength increases.

Answer:

frequency will decrease and the wavelength will increase