Which of the following best describes the relationship between the energy of a photon and its frequency?

• A. The energy of a photon is directly proportional to its frequency, given by E = hu.
• B. The energy of a photon is inversely proportional to its frequency, given by E = h/u.
• C. The energy of a photon is proportional to the square of its frequency, given by E = hu^2.
• D. The energy of a photon is independent of its frequency.

Answer: (A)

Verified step by step guidance

1. Recall the fundamental relationship between the energy of a photon and its frequency, which is derived from quantum theory.
2. Understand that the energy of a photon (E) is directly proportional to its frequency (\( \nu \)), meaning as frequency increases, energy increases linearly.
3. Use the equation that relates energy and frequency: \( E = h \nu \), where \( h \) is Planck's constant, a fundamental constant in physics.
4. Recognize that the other options (inverse proportionality, proportional to the square of frequency, or independence from frequency) do not align with the established quantum mechanical relationship.
5. Conclude that the correct description is that the energy of a photon is directly proportional to its frequency, expressed mathematically as \( E = h \nu \).