All radioactive emissions ionize gases

Steps:

• Identify the three main types of radioactive emissions: alpha particles, beta particles, and gamma rays.
• Recall properties: alpha and beta are charged particles; gamma is electromagnetic radiation.
• Evaluate each option against all three types for universal applicability.
• Confirm only ionization is a shared effect, as all emissions interact with matter to produce ions.

Why D is correct:

• Radioactive emissions are ionizing radiation by definition, as they carry enough energy to strip electrons from atoms, creating ion pairs in gases per the ionization chamber principle.

Why the others are wrong:

• A: Gamma rays penetrate aluminum, unlike alpha and beta.
• B: Gamma rays, being neutral, are not deflected by electric fields.
• C: Gamma rays are unaffected by magnetic fields due to lack of charge.

Final answer: D