Mendeleev
Science & measurement
Science · V3 recovery
Photon energy and wavelength
A photon connects energy and wavelength through E = hν = hc/λ. Shorter wavelengths correspond to higher photon energies. This simple relation links spectroscopy, colour, ultraviolet radiation, X-rays and atomic transitions. The Planck constant h and the speed of light c are defining constants in the modern SI.
Understand the idea
Photon energy and wavelength
1 · Understand the idea2 · How to use this concept3 · Try it yourself
Start by identifying what the page is describing, which quantities or structures are involved, and what changes when one parameter changes. Separate the definition from the consequence: a scientific term is useful only when you can connect it to an observation, a calculation or a position in the periodic table.
Worked reading
How to use this concept
Read the statement once without calculating. Then list the known information, the unknown, the units and the relation that connects them. If a diagram is present, name every symbol before using it. Finally, check whether the result is physically and chemically plausible rather than accepting a number simply because the arithmetic worked.
Key point
A photon connects energy and wavelength through E = hν = hc/λ. Shorter wavelengths correspond to higher photon energies. This simple relation links spectroscopy, colour, ultraviolet radiation, X-rays and atomic transitions. The Planck constant h and the speed of light c are defining constants in the modern SI.
Try it yourself
Photon energy and wavelength
Use the explanation above to restate the concept in one sentence, then identify one concrete example from the page. If a formula is involved, explain what each symbol means before substituting values.
Show the answer
A photon connects energy and wavelength through E = hν = hc/λ. Shorter wavelengths correspond to higher photon energies. This simple relation links spectroscopy, colour, ultraviolet radiation, X-rays and atomic transitions. The Planck constant h and the speed of light c are defining constants in the modern SI.