Question

which of the following describes photons? select two.
□ massless particles
□ carry mass
□ found in mechanical waves
□ carry energy

Explanation:

Photons are fundamental particles of light (electromagnetic radiation). Key properties: they have no rest mass (massless), and they carry energy (e.g., via the relation $E = h
u$, where $h$ is Planck's constant and $
u$ is frequency). Mechanical waves (like sound) do not involve photons.

Answer:

massless particles, carry energy