Ernest Rutherford articulates his model of the atom, at the center of which exists a nucleus containing the majority of the atom's mass and all of its positive charge.

French physicist Henri Becquerel discovers radioactivity.

The British Admiralty accepts Leo Szilard's offer to turn over his patents.

The British War Office rejects Leo Szilard's offer to turn over to them his patents of nuclear energy for free, an offer made to bring them under British secrecy laws.

Ida Noddack publishes a paper in Zeitshrift fur Angewandte Chemie arguing that the anomalous radioactivities produced by neutron bombardment of uranium may be due to the atom splitting into smaller pieces.