A minute bundle of pure energy that has no weight or mass is called what?

• A. Penumbra
• B. Photon
• C. Primary Radiation
• D. Radiograph

Answer: (B)

Light can be described as particles called photons, which are tiny bundles of energy with no rest mass. A photon carries energy that depends on its frequency and always moves at the speed of light in a vacuum. Because it has zero rest mass, it behaves like a quantum of electromagnetic radiation rather than a conventional material particle. This makes photons the exact term for a minute bundle of pure energy with no weight or mass.

Penumbra is the partial shadow around an object, not a particle of energy. Primary Radiation is a general term for the initial radiation but doesn’t name a specific energy packet. Radiograph is an image produced when radiation exposes a detector or film, not the energy packet itself.