Development of the periodic table By Gladshed man Jan 25, 1669 discovery of phosphorus By Hennig brand Jan 1, 1680 Robert Boyle discovers phosphorus and makes it public Jan 1, 1780 Johann Dobreiner develops the first periodic table Jan 1, 1809 patterns between 47 known elements are discovered Jan 1, 1829 Dobreiner's law of triads Jan 1, 1863 law of octaves and John newland develops the catagorisation of the 56 known elements Jan 1, 1886 Radioactivity discovered Jan 1, 1887 henry moseley performs x-rays on known elements and notices more patterns between them Jan 1, 1894 Noble gases are discovered Jan 1, 1897 J.J thompson discovers electrons Jan 1, 1900 beta particles discovered Jan 1, 1903 break down of atoms is caused by radioactivity Jan 1, 1914 Protons in the atomic nucleus Jan 1, 1932 Lanthanides and actinides Jan 1, 1932 Neutrons and isotopes Jan 1, 1960 60 elements discovered Jan 31, 2012 Electrons orbit the nucleus is discoverd