Gamma radiation consists of electromagnetic waves

Steps:

• Recall alpha radiation: helium nuclei (particles).
• Recall beta radiation: high-speed electrons or positrons (particles).
• Recall gamma radiation: high-energy photons (electromagnetic waves).
• Compare to options: only gamma qualifies as waves.

Why C is correct:

• Gamma rays are electromagnetic radiation, propagating as transverse waves per Maxwell's equations.

Why the others are wrong:

• A: Alpha particles are charged helium ions, not waves.
• B: Beta particles are electrons/positrons with mass, behaving as particles.
• D: Includes alpha and beta, both particulate, excluding gamma waves.

Final answer: C