Q.Prepare a chart of comparative properties of the alpha (α), beta (β) and gamma (γ) radiations.

Step 1. Identity: an alpha particle is a helium-4 nucleus (4-2-He, 2 protons + 2 neutrons); a beta particle is a high-speed electron (0,-1,e) ejected from the nucleus; a gamma ray is a high-energy photon (electromagnetic radiation), not a particle of matter at all.

Step 2. Charge: alpha = +2; beta = -1; gamma = 0 (neutral).

Step 3. Mass: alpha = 4 u (relatively heavy); beta = negligible (an electron's mass, about 1/1837 of a proton's); gamma = 0 rest mass.

Step 4. Speed: alpha particles are comparatively slow (a small fraction of light speed) because of their larger mass; beta particles are much faster; gamma rays travel at the speed of light.

Step 5. Penetrating power (weakest to strongest): alpha is stopped by a sheet of paper or the outer layer of skin; beta needs a few millimetres of aluminium to stop it; gamma needs several centimetres of lead or a thick slab of concrete.

Step 6. Ionising power runs the opposite way: alpha ionises matter most strongly (over a very short range), beta less so, gamma the least per interaction (though it can penetrate deep and cause damage over a longer path).

Step 7. Deflection in electric/magnetic fields: alpha deflects slightly (heavy, low charge-to-mass ratio) toward the negative plate; beta deflects strongly (light, high charge-to-mass ratio) toward the positive plate; gamma, being uncharged, is not deflected at all.

List identity, charge, mass, speed, penetrating power, ionising power and field-deflection for each of the three radiation types, then arrange them as a comparison chart/table.

• Confusing beta particles (fast electrons from the nucleus) with ordinary atomic electrons.
• Assuming gamma rays are particles of matter rather than electromagnetic radiation.
• Getting penetrating power backwards (alpha is the WEAKEST penetrator despite being the most massive, because it interacts most strongly and loses energy fastest).