1887-1915

English physicist who derived the relationship between an element's x-ray wavelengths and atomic number—Moseley's Law. This allowed him to assign characteristic numbers to each element and order them into a periodic table. Moseley then predicted the existence of several undiscovered elements. He was able to predict their spectral patterns, which proved invaluable in the search and later discovery of these elements. Moseley was killed at the battle of Sulva Bay during World War I.