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Otto Hahn

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Otto Hahn was a famous German chemist who changed how we understand the tiny building blocks of our world.

Otto Hahn (Frankfurt)
Otto Hahn (Frankfurt)

He is known as a pioneer in radiochemistry, which is the study of radioactive materials. Hahn is often called the father of nuclear chemistry. This is because he helped discover nuclear fission. Nuclear fission is the process where the center of an atom splits apart. This discovery is the science used in nuclear reactors and nuclear weapons.

Nuclear Fission Experimental Apparatus 1938 - Deutsches Museum - Munich
Nuclear Fission Experimental Apparatus 1938 - Deutsches Museum - Munich

His work helped people understand the huge amount of energy hidden inside atoms.

To find these secrets, Hahn had to look very closely at how elements change. He studied how certain substances act when they are hit by particles called neutrons. Between 1934 and 1938, Hahn worked with Fritz Strassmann and Lise Meitner on this hard job. They looked at isotopes created by hitting uranium and thorium with neutrons. An isotope is a version of a chemical element. They found that the uranium was actually splitting into smaller pieces.

Otto Hahn's notebook 1938 - Deutsches Museum - Munich
Otto Hahn's notebook 1938 - Deutsches Museum - Munich

This step-by-step discovery showed exactly how the atom breaks apart and releases energy.

Hahn's journey into science began with a lot of travel and study. He earned his doctorate at the University of Marburg in 1901.

München-2025-Deutsches Museum-Hahn
München-2025-Deutsches Museum-Hahn

To learn more, he went to London to work under Sir William Ramsay. Later, he moved to Montreal, Canada, to assist the famous Ernest Rutherford.

Ernest Rutherford 1905
Ernest Rutherford 1905

In Canada, he worked in a basement at McGill University. Rutherford even said that Hahn had a "special nose" for finding new elements. These years of training helped him become an expert in his field.

Throughout his life, Hahn made many important discoveries with specific dates and places. In 1905, while in London, he discovered a substance he called radiothorium.

William Ramsay
William Ramsay

When he returned to Germany, he worked in a former woodworking shop in Berlin. He and Lise Meitner worked together for thirty years. In 1918, she isolated a long-lived version of the element protactinium. For his big discovery of fission, Hahn was awarded the Nobel Prize in Chemistry in 1944.

Otto Hahn Nobelpreis 1945-a
Otto Hahn Nobelpreis 1945-a

He also led the Max Planck Society from 1948 to 1960.

Hahn's life shows how science connects to the real world. His work with atoms led to new ways to make electricity.

Decay Chain of Uranium-238corrected
Decay Chain of Uranium-238corrected

He also cared deeply about how scientists behave. In 1959, he helped start a group called the Federation of German Scientists. This group wanted to make sure science is used in a responsible way. Even during difficult times like World War II, he stayed focused on his research.

Berliner Physiker u Chemiker 1920
Berliner Physiker u Chemiker 1920

Today, his name is remembered as a leader who helped rebuild science in Germany.

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🖼️ Images & Media (20)
File:William Ramsay.jpg
William Ramsay.jpg
File:Ernest Rutherford 1905.jpg
Ernest Rutherford 1905.jpg
File:Otto Hahn und Lise Meitner.jpg
Otto Hahn und Lise Meitner.jpg
File:Berliner Physiker u Chemiker 1920.jpg
Berliner Physiker u Chemiker 1920.jpg
File:Dahlem Thielallee Hahn-Meitner-Bau.JPG
Dahlem Thielallee Hahn-Meitner-Bau.JPG
File:Ottohahn1915.jpg
Ottohahn1915.jpg
File:Decay Chain of Actinium.svg
Decay Chain of Actinium.svg
File:Decay Chain of Uranium-238corrected.svg
Decay Chain of Uranium-238corrected.svg
File:München-2025-Deutsches_Museum-Hahn.jpg
München-2025-Deutsches_Museum-Hahn.jpg
File:Nuclear Fission Experimental Apparatus 1938 - Deutsches Museum - Munich.jpg
Nuclear Fission Experimental Apparatus...
File:Otto Hahn's notebook 1938 - Deutsches Museum - Munich.jpg
Otto Hahn's notebook 1938 - Deutsches...
File:Dahlem Thielallee Hahn-Meitner-Bau-2.JPG
Dahlem Thielallee Hahn-Meitner-Bau-2.JPG

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