Marie Curie was born in Poland but studied and carried out her research in Paris. In 1903, she shared the Nobel Prize in Physics with H. Becquerel and her husband Pierre for their discovery of radioactivity. (In 1911 she received the Nobel Prize in Chemistry for the discovery of two new chemical elements, radium and polonium, the latter named for her homeland, Poland.) They and others observed that a radioactive substance could emit three types of radiation: alpha (α), beta (β), and gamma (γ). If the radiation from a radioactive source is passed between electrically charged plates, some particles are attached to the positive plate, some to the negative plate, and others feel no attraction. Which particles are positively charged, which are negatively charged, and which have no charge? Of the two charged particles, which has the most mass? 

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Photographic film- or phosphor screen Lead block shield Slit Radioactive element B particles, attracted to + plate Charged plates ẞ particles a particles, attracted to - plate 7 rays a particles Radioactivity. Alpha (a), beta (B), and gamma (y) rays from a radioactive element are separated by passing them between electrically charged plates.