Physics
Intermediate

Energy of a Photon

Energy of a photon from its frequency.

Formula

E=hfE = hf

Variables

hPlanck constant
fFrequency

Example

A photon of green light (~5.5×10¹⁴ Hz) carries E = h·f ≈ 3.6×10⁻¹⁹ J.

Did You Know?

Einstein won his Nobel Prize not for relativity but for explaining that light energy comes in these discrete photon packets.