Marie Curie and the Discovery of Radioactivity

Marie Sklodowska Curie was born in Warsaw in 1867, when Poland was under Russian control. She later became the first woman to win a Nobel Prize and the only person to win Nobel Prizes in two different sciences. She won the Nobel Prize in Physics in 1903, shared with her husband Pierre Curie and with Henri Becquerel, and the Nobel Prize in Chemistry in 1911 for her work on polonium and radium. Her research founded the modern study of radioactivity. This article follows her path from Warsaw to Paris and explains what her discoveries meant for science, medicine and war.

Education in Warsaw and Paris

Women could not attend the main universities in Russian-ruled Warsaw in the 1880s. Young Polish students, including Sklodowska, took part in an underground educational network sometimes called the Flying University. She worked as a governess to earn money and saved enough to travel to Paris in 1891. At the Sorbonne she studied physics and mathematics, earning degrees in 1893 and 1894.

Paris gave her access to laboratories and scientists who were studying new phenomena. The city was the center of research in physics at the time, and she made use of its equipment and networks. She also met Pierre Curie, a physicist who worked on magnetism and crystals. They married in 1895 and became a scientific partnership.

Becquerel's rays and Curie's question

In 1896, Henri Becquerel discovered that uranium salts emitted penetrating rays that could darken photographic plates even in the dark. Curie chose this phenomenon as the subject of her doctoral research. She wanted to know whether the rays came from the atoms themselves and whether other materials also emitted them.

Curie measured the rays with an electrometer, a device that detected the electric charge created when the rays ionized the air. She found that thorium also emitted rays. More importantly, she noticed that a mineral called pitchblende was more active than uranium alone would explain. Her conclusion was bold. The activity must come from new elements that had not yet been identified.

Polonium and radium

In July 1898, Marie and Pierre Curie announced the discovery of polonium, a new element more radioactive than uranium. Marie named it after Poland, her homeland, as a quiet protest against its partition. A few months later, in December 1898, they announced radium, another new and intensely radioactive element.

Isolating these elements was a huge challenge. Pitchblende contained tiny amounts of radium mixed with other materials, and the Curies had to process large quantities of ore. In 1902, Marie reported that she had isolated a decigram of radium chloride after processing several tons of pitchblende. The work was physically demanding and done in a crude shed with little protection from the materials they handled.

Element	Year announced	Notable fact
Polonium	1898	Named after Poland
Radium	1898	Isolated as a salt in 1902

The 1903 Nobel Prize

In 1903, the Nobel Prize in Physics was awarded to Henri Becquerel and to Pierre and Marie Curie for their work on radiation. Marie became the first woman to receive a Nobel Prize. The recognition brought public attention to the field, and it also gave the Curies greater resources for their laboratory work.

The period was difficult in personal terms. Pierre was injured in a street accident in 1906 and died shortly after. Marie then took over his teaching position at the Sorbonne and became the first woman to teach there. She continued her research while raising two daughters, and she faced public criticism when her relationship with another scientist became known.

The 1911 Nobel Prize in Chemistry

In 1911, Marie Curie received a second Nobel Prize, this time in Chemistry. The award honored her discovery of polonium and radium, her work on the properties of radium, and her isolation of radium metal. Few scientists had ever received a Nobel Prize in two different fields, and her double award remains rare.

Her work on chemical properties was as important as the discovery of the elements. She showed that radioactivity was a property of atoms rather than a result of chemical reactions. This idea changed how scientists understood matter and energy, and it helped prepare the ground for later work in nuclear physics.

Radiation in medicine and war

Radium quickly found uses in medicine. Physicians used it to treat cancer, and radioactive sources became part of the early tools for radiation therapy. The dangers of radiation were not understood at first, and many early workers, including the Curies, were exposed without adequate protection. Radium was also sold in products such as cosmetics and tonics, which later caused serious harm.

During the First World War, Curie organized mobile X-ray units that could be taken close to the front. Doctors used them to locate bullets and fractures in wounded soldiers. She trained women to operate the equipment, and the units became known in France as petites Curies. Her wartime work showed how scientific knowledge could save lives when applied directly to the battlefield.

Death, legacy and the Radium Institute

Curie's health declined in the last years of her life. Her research had exposed her to radiation for decades, long before the risks were well understood. Her laboratory work relied on bare hands, open dishes and simple glassware, because no shielding standards for radioactive materials existed in her early career. Her later career at the Radium Institute continued the same pattern of rigorous measurement, and it shows how scientific practice and personal safety were still learned in parallel.

Curie died in 1934 from aplastic anemia, a blood disorder that is widely believed to have been caused by her long exposure to radiation. Her notebooks, papers and personal items remain radioactive, and they are kept under special conditions. Visitors who wish to consult them must follow strict safety rules.

Her institutions outlived her. The Radium Institute in Paris, now part of the Institut Curie, was founded in 1909 as a center for research and cancer treatment. A similar institute was later established in Warsaw. These centers continue to work on cancer research and medicine, extending the practical goals that Curie pursued throughout her life.

Key takeaways

Marie Curie helped discover polonium and radium, and she showed that radioactivity is a property of atoms. Her two Nobel Prizes, in physics and in chemistry, recognized work that opened a new field of science. Her research led to medical treatments and to wartime X-ray units that saved lives.

Her career also carries a warning. Radiation brought great benefits, but its dangers were not understood early enough, and the cost fell on the researchers who handled it. Her story combines brilliant discovery, personal sacrifice and the responsibility that comes with new knowledge.