Marie Curie’s work, nuclear instability, the nature and properties of alpha, beta and gamma radiation, their ranges, deflection in fields, cloud-chamber tracks, and nuclear equations.
5 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
Marie Curie won two Nobel Prizes for discovering that certain elements release energy from their nuclei, and she carried samples in her pockets without knowing the danger.
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Copy these into your notebook in your own words — that is how they stick.
Spontaneous disintegration of an unstable nucleus; random and unaffected by external conditions.
Discovered polonium and radium; Nobel Prizes in Physics (1903) and Chemistry (1911).
Helium nucleus, +2; stopped by paper; most ionising.
Fast electron, −1; stopped by a few mm of aluminium.
E.m. radiation; reduced by thick lead; least ionising; not deflected.
α and β in opposite directions; β more; γ none.
α short thick; β thin wavy; γ faint.
α: A −4, Z −2; β: Z +1; γ: no change.
3 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness. More games in the Physics Arcade.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better. Work each item on paper first.
Write full answers, then reveal the mark scheme and tick the points you earned (15 marks in total). Show all your working — method marks count. Your answers are saved on this device.
Question 1 [15 marks]
A radioactive source emits alpha, beta and gamma radiation.
(a) (a) Define radioactivity. [2]
(b) (b) State the nature of (i) alpha particles, (ii) beta particles and (iii) gamma rays. [3]
(c) (c) State what is needed to stop each radiation: alpha, beta, gamma. [3]
(d) (d) Describe what happens to α, β and γ radiation as they pass through a magnetic field. [3]
(e) (e) Complete the nuclear equation for the alpha decay of radium-226 (Z = 88) to radon. [2]
(f) (f) Describe the tracks left in a cloud chamber by alpha and beta particles. [2]
Find these in your own past-paper booklets for extra timed practice. Items above are written in the style of these papers; any adapted from a specific question say so.