Linked from

The 4 pages that link to Planck relation, each with the reason it gives.

• PhotonRelated: It quantifies how photon energy changes with electromagnetic frequency.

• Electromagnetic spectrumRelated: It explains why high-frequency bands carry more energetic photons.

• Spectral lineRelated: It converts a line's measured frequency into the energy of its transition.

• X-rayRelated: It connects X-ray frequency and wavelength to the energy measured in electronvolts.