How does a photon's wavelength relate to its energy?

The energy of a photon is inversely proportional to its wavelength. This relationship is derived from the fact that photon energy (E) is directly proportional to its frequency ($\nu$), expressed by the equation $E=h\nu$, where h is Planck’s constant.123

Because the frequency of light is related to its wavelength ($\lambda$) and the speed of light (c) by the formula $\nu =c/\lambda$, the energy of a photon can be expressed as:

$$E=\frac{hc}{\lambda }$$

This means that as the wavelength of a photon increases, its energy decreases, and conversely, as the wavelength decreases, the energy of the photon increases.3