Hiding a Nobel Prize From the Nazis

During WWII, Nobel laureates Max von Laue and James Franck sent their gold medals to Niels Bohr in Denmark to protect them from the Nazis. Chemist George de Hevesy dissolved the medals in Aqua regia to hide them. Aqua regia, a mix of nitric and hydrochloric acids, can dissolve gold by shifting the reaction equilibrium. After the war, the gold was recovered and the medals were remade. This story highlights the chemistry of noble metals and the clever use of reversible reactions.

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