The year 1913 in science and technology.

Chemistry

• Protactinium was first identified by Kasimir Fajans and O. H. Göhring
• Henry Moseley shows that nuclear charge is the real basis for numbering the elements and discovers a systematic relation between wavelength and atomic number by using x-ray spectra obtained by diffraction in crystals.

Physics

• William Henry Bragg and William Lawrence Bragg work out the Bragg condition for strong X-ray reflection
• Niels Bohr presents his quantum model of the atom
• Robert Millikan measures the fundamental unit of electric charge
• Johannes Stark demonstrates that strong electric fields will split the Balmer spectral line series of hydrogen

Geology

• Albert Michelson measures tides in the solid body of the Earth

Technology

• Kinemacolor, the first commercial "natural color" system for movies is invented

Nobel Prizes

• Heike Kamerlingh-Onnes is awarded the Nobel Prize for Physics
• Alfred Werner is awarded the Nobel Prize for Chemistry
• Charles Robert Richet is awarded the Nobel Prize for Medicine

Births

• March 26 - Paul Erdös (d. 1996), mathematician.

Deaths

• January 2 - Léon Teisserenc de Bort (b. 1855), meteorologist.
• May 28 - John Lubbock (b. 1834), naturalist and archaeologist.
• November 7 - Alfred Russel Wallace (b. 1823), biologist.