August Karl Krönig (20.09.1822-5.06.1879) was a German physicist. He was born in Schildesche. He studied at the University of Bonn. In 1845 he completed his doctoral dissertation under G. Magnus at the University of Berlin, and he was professor at the university (until 1861). He edited the first German physics journals.
He proposed (1856) treating a gas as a collection of randomly moving elastic spheres (the ideal-gas model). He was the first to suggest applying probabilistic methods of calculation to the description of molecular motion. He proved Avogadro's law.