Swedish chemist who explained the electrical conductivity of ionic solutions by presuming that compounds dissociated into oppositely charged ions whose motions constituted a current. This conclusion was supported by observing that the freezing point depression of ionic solids were integer multiples larger than their concentrations would indicate according to Raoult's Law. He described his theory in his 1884 thesis, which passed the defense with the lowest passing grade. However, it won him the Nobel Prize in chemistry in 1903. He also discovered the Arrhenius Rate Law, which describes the rate at which chemical reactions occur.

In Worlds in the Making (1908), he suggested that life on Earth had begun when space-traveling spores reached Earth. He also argued against the ultimate implication of the third law of thermodynamics known as Heat Death.

Additional biographies: Bonn