In photon energy terms, which statement is correct regarding wavelength?

• A. Shorter wavelengths have higher energy than longer wavelengths.
• B. Shorter wavelengths have lower energy than longer wavelengths.
• C. Wavelength does not affect energy.
• D. All wavelengths have the same energy.

Answer: (A)

Photon energy depends on wavelength: shorter wavelengths carry more energy per photon. This comes from E = hν = hc/λ, so as wavelength gets smaller, frequency and energy rise. For example, violet light (400 nm) has higher energy per photon than red light (700 nm). That’s why the statement that shorter wavelengths have higher energy is the correct one. The other ideas—that wavelength doesn’t affect energy, that all wavelengths have the same energy, or that shorter wavelengths have lower energy—don’t match the fundamental relation between energy and wavelength.