Matching radiation descriptions to standard names

Steps:

• Identify helium nuclei as alpha particles, which are two protons and two neutrons.
• Recognize short wavelength electromagnetic waves as gamma rays, high-energy photons.
• Classify electrons as beta particles, high-speed electrons from neutron decay.
• Match the given order: helium nuclei (alpha), electromagnetic waves (gamma), electrons (beta).

Why A is correct:

• Alpha particles are defined as helium-4 nuclei (He²⁺), gamma rays as electromagnetic radiation with wavelengths below 10 pm, and beta particles as electrons (or positrons) emitted in decay.

Why the others are wrong:

• B: Incorrect order; lists beta first, not matching helium nuclei.
• C: Starts with gamma, mismatching the helium nuclei description.
• D: Begins with gamma and follows with beta, skipping alpha for helium nuclei.

Final answer: A