Saha, ionization equation
16 February 1920 Death of Paul Friedrich Ferdinand Kempf in Potsdam, Germany
2 December 1920, Birth of William de Wiveleslie Abney in Folkestone, Kent, England
1920 Birth of Chusiro Hayashi
1920 Birth of Rosalind (Elsie) Franklin
1920 Birth of Thomas Gold
1920 Birth of Keith R Symon
1920 Birth of Sir John Adams
1920 Birth of Mervyn Hine
1920 Birth of Hugh Hereward
Physics to Charles Edouard Guillaume in recognition of the service he has rendered to precision measurements in Physics by his discovery of anomalies in nickel steel alloys.
Chemistry to Walther Hermann Nernst "in recognition of his work in thermochemistry"
Physiology or Medicine to Schack August Steenberg Krogh "for his discovery of the capillary motor regulating mechanism"