jan 1, 1913 - Henry Moseley

Description:

Henry Moseley reported that the frequencies are proportional to the squares of whole numbers that are equal to the atomic number plus a constant. Known as Moseley’s law, this fundamental discovery concerning atomic numbers was a milestone in advancing the knowledge of the atom. Moseley also published a paper in which he concluded that there were three unknown elements between aluminum and gold (there were four). He also concluded correctly that there were only 92 elements up to and including uranium and 14 rare-earth elements.

Added to timeline:

Date:

Images: