November 7, 2010

Happy Birthday, Marie Curie and Lise Meitner

Two different eminent female scientists who did important pioneering work in the field of radioactivity were born on this day. Curie was born Maria Skłodowska in 1867, in Warsaw, Poland (at the time Warsaw was part of the Russian empire); most of her adult life and work were in France. Meitner was born in Austria in 1878, and (because she was Jewish) she later had to flee from the Nazis and ended up in Sweden.

Curie and her husband Pierre did experiments on uranium minerals and discovered two new elements, polonium and radium. Curie won two different Nobel prizes for her work (in Physics and Chemistry)—the first person in the world ever to win two, and still the only woman to win in two different fields. She coined the word radioactivity, invented techniques for isolating radioactive isotopes, and even did the world's first studies on radiation treatment of cancer. Sadly, she died from radiation poisoning.

As we learned yesterday, curium (atomic number 96) is named for Marie and Pierre Curie.

Meitner and her colleague Otto Hahn discovered nuclear fission. Although Hahn received a Nobel prize for the discovery, Meitner was overlooked—an omission that many people think was terrible. Meitner and Hahn's work explained why fission released energy, exactly how uranium breaks down into lighter elements, and why no stable elements heavier than uranium exist in nature.

The element meitnerium (atomic number 109) is named for Meitner.

Learn about nuclear physics!

Atoms are basically made up of heavy particles called protons and neutrons, which are found in the center (or nucleus) of the atom, and a surrounding cloud of teensy, almost weightless particles called electrons. A particular element is defined as having a certain atomic number, which is the number of protons that element has.

If an atom of a particular element loses or gains an electron or two, it is called an ion.

If an atom of a particular element has more or fewer neutrons than usual, it is called an isotope.

But if an atom of a particular element loses or gains a proton—it becomes another element!

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