Marie Skłodowska Curie was a physicist and chemist whose work changed how scientists understand matter, atoms, and energy. Born in Warsaw in 1867, she moved to Paris to study science and became the first woman to win a Nobel Prize. With Pierre Curie and Henri Becquerel, she shared the 1903 Nobel Prize in Physics for research on radioactivity.
She later won the 1911 Nobel Prize in Chemistry for discovering and studying the elements polonium and radium.
Key Facts
- Marie Curie coined the term radioactivity to describe spontaneous radiation from unstable atoms.
- Radioactive decay follows N = N0(1/2)^(t/T), where T is the half-life.
- Activity is the number of decays per second: A = λN.
- Alpha radiation is a helium nucleus, beta radiation is a high-speed electron or positron, and gamma radiation is high-energy electromagnetic radiation.
- Curie discovered polonium in 1898 and named it after Poland, then helped isolate radium from pitchblende.
- During World War I, Curie helped develop mobile X-ray units called Little Curies to locate bullets and fractures in wounded soldiers.
Vocabulary
- Radioactivity
- Radioactivity is the spontaneous emission of particles or electromagnetic radiation from unstable atomic nuclei.
- Half-life
- Half-life is the time required for half of the radioactive nuclei in a sample to decay.
- Radium
- Radium is a highly radioactive element discovered by Marie and Pierre Curie in uranium ore.
- Polonium
- Polonium is a radioactive element discovered by Marie Curie and named for her homeland, Poland.
- X-ray
- An X-ray is a high-energy electromagnetic wave that can pass through soft tissue and reveal denser materials such as bone.
Common Mistakes to Avoid
- Thinking Curie invented radioactivity, which is wrong because radioactivity is a natural atomic process that she named and investigated experimentally.
- Treating half-life as the time for all atoms to decay, which is wrong because each half-life reduces the remaining undecayed nuclei by half.
- Assuming all radiation is equally penetrating, which is wrong because alpha, beta, and gamma radiation have different masses, charges, and penetrating abilities.
- Ignoring safety when discussing early radium research, which is wrong because Curie worked before modern radiation protection and prolonged exposure can damage living tissue.
Practice Questions
- 1 A 40.0 g sample of a radioactive material has a half-life of 5.0 years. How much undecayed material remains after 15.0 years?
- 2 A radioactive sample contains 2.0 x 10^12 unstable nuclei and has a decay constant of 3.0 x 10^-5 s^-1. What is its activity in becquerels?
- 3 Explain why Marie Curie's discovery that radioactivity comes from atoms themselves was important for the development of modern atomic physics.