Spectroscopy and the atomic number

Scientists began to group the elements together according to their similarities after the discovery of elements occurred through the 1800s. Alexandre-Emile Béguyer de Chancourtois, a French geologist, was the first person to publish a chart in an attempt to systematize elements by properties. This figure, meant to be displayed on the surface of a tube so that the lines plot out a spiral, used more accurate measures of atomic mass that came out in 1858. In 1862, German chemist Julius Lothar Meyer developed a table that not only had gaps to accommodate potentially new elements, but also included at least one deviation from a strict ordering by atomic mass. In 1869, Russian chemist Dmitri Mendeleev published his version of a periodic table complete with gaps and predictions for the chemical and physical properties of the elements that would fit in those gaps. In 1971, Rutherford's team produced hydrogen nuclei when bombarding nitrogen gas with alpha particles, leading Rutherford to conclude that hydrogen nuclei were actually a component of the nitrogen nucleus.