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The start of the development of the Periodic table
Dmitri Mendeleev ( a Russain chemist) started the development of the periodic table by arranging elements by atomic mass -
The discovery of the noble gases
Sir William Ramsay & Lord Rayleigh discovered the noble gases, which were added to the periodic table as group 0 -
The discovery of electrons
J.J Thomson discovers the electrons which are used to used to find out how reactive a element is -
The discovery of orbit
Ernest Rutherford and Hans Grieger discover that electrons orbit the nucleus of an atoms in elements. -
The discovery of protons
Ernest Rutherford discovers protons in the atomic nucleus. -
Atomic numbers
Henry Moseley creates atomic numbers, which are based on the number of eletrons in an atom. -
The complete basis of the periodic table
James Chadwick dicovers neutrons in the nucleus and isotopes are discovered. This completed the basis of the periodic table. -
Lanthanides ans actinides
Glenn Seaborg identifies lanthanides and actinides. Which are usually seen under the periodic table.
