What is the smallest unit of radiant energy that makes up light waves and radio waves?

What is the smallest unit of radiant energy that makes up light waves and radio waves?

• A. Photon
• B. Quanta
• C. Spark
• D. Flux

Answer: (A)

Electromagnetic radiation comes in discrete energy packets rather than a continuous flow. The smallest unit of radiant energy for light and radio waves is a photon. Each photon carries energy E = h f (Planck’s constant times the frequency), so higher-frequency waves have more energetic photons while lower-frequency waves, like radio waves, have photons with very small energy. The overall wave can contain many photons, and its intensity depends on how many photons are present. The term quanta is a general way to refer to these discrete packets, but the specific unit for electromagnetic radiation is the photon. A spark isn’t related, and flux describes a rate of flow, not a single energy unit.

Electromagnetic radiation comes in discrete energy packets rather than a continuous flow. The smallest unit of radiant energy for light and radio waves is a photon. Each photon carries energy E = h f (Planck’s constant times the frequency), so higher-frequency waves have more energetic photons while lower-frequency waves, like radio waves, have photons with very small energy. The overall wave can contain many photons, and its intensity depends on how many photons are present. The term quanta is a general way to refer to these discrete packets, but the specific unit for electromagnetic radiation is the photon. A spark isn’t related, and flux describes a rate of flow, not a single energy unit.