dec 31, 1912 - Henry Moseley- 1913 he observed the X-ray spectra of elements and found a direct relationship between the wavelengths of the elements spectra and the atomic number of the element (Moseley’s law). Shot and killed at the age of 27 during the Battle of Gallipoli.
Added to timeline:
Date:
dec 31, 1912
Now
~ 112 years ago