Development of the Periodic table By Alex B.B 10MK

By 501951
  • 100

    Egyptians formulate theory of Ogdoad (3000 B.C)

    The Egypyians had supposedly formulated the theory of what was called the "Ogdoad". The Ogdoad had consisted of four Gods. Each pair was male and female, and they had four creative powers or sources. The Egyptians believed that these forces had exsisted before the creation of the sun.
  • 150

    Egyptian King: Hermes Trismegistus (1900 B.C)

    Supposedly, there was a semi-mythical Egyptian king, who had supposedly founded the art of alchemy. Alchemy is: The medieval forerunner of chemistry, concerned with the transmutation of matter, in particular with attempts to convert base metals into gold or find a universal elixir. So basically, this Egyptian king somehow knew how to convert metals into gold.
  • 200

    Empedocles says that there are four elements (450 B.C)

    Empedocles was a Greek pre-Socratic philosopher and a citizen of Agrigentum, a Greek city in Sicily. Empedocles said that all things have four elements. These are: earth, fire, air and water.
  • 250

    Democritus states the idea of an atom (440 B.C)

    Democritus was an Ancient Greek philosopher born in Abdera, Thrace, Greece. He was an influential philosopher who had thought of the idea of an atomic theory for the universe.
  • 300

    Aristotle expresses his theory of the five elements, fire, water, earth, air, and ether (350 B.C)

    Aristotle was a Greek philosopher. Aristotle wrote about things such as physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology. He had thought of the five elements that make up the world such as; fire, water, earth, air, and ether.
  • Robert Boyle

    Robert Boyle proposes Boyle's Law on the behavior of gases
  • Phosphorus was discovered

    Phosphorus was discovered by a German merchant and amateur alchemist Hennig Brand attempted to created a Philosopher’s Stone. This was supposeldy where an object could turn metals into gold. To prove his theory, he heated up some remains of boiled urine, and a liquid dropped out and burst into flames. This was the first discovery of phosphorus.
  • Period: to

    Discoveries of the Periodic elements

    Between the year of 1735 and 1952, many, or if not, all of the priodic elements were discoevred by many people. There are still many elements that are still unknown to us, and there will be many still to be discovered.
  • Antoine Lavoisier

    Antoine Lavoisier recognizes and names oxygen, and recognizes its importance and role in combustion.
  • English Chemist John Newlands

    Chemist John Newlands divided the discovered 56 elements into 11 groups, based on characteristics.
  • Russian Chemist Dimitri Mendeleev started the development of the Periodic table

    In 1869, a Russian Chemist called Dimitri Mendeleev started the development of the Periodic table. He had started to arrange the periodic elements by their atomic mass.
  • French physicist Antoine Bequerel first discovers radioactivity

    French physicist Antoine Bequerel first discovers radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. They discovered that beta particles were negatively charged.
  • Sir William Ramsay and Lord Rayleigh discovered the noble gases

    Sir William Ramsay and Lord Rayleigh discovered the noble gases These were added to the periodic table as group 0.
  • English physicist J. J. Thomson first discovered electrons

    English physicist J. J. Thomson first discovered electrons. He found out that electrons were mall negatively charged particles in an atom. From this information that he had gathered, John Townsend and Robert Millikan then found out their exact change, and also mass.
  • Bequerel discovery with electrons and beta particles

    Bequerel discovered that electrons and beta particles as identified by the Curies are the same thing.
  • Rutherford

    Rutherford announced that radioactivity is caused by the breakdown of atoms.
  • Rutherford and German physicist Hans Geiger

    Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.
  • Discovery by Bohr

    Bohr discovered that electrons move around a nucleus in discrete energy called orbitals. Radiation is emitted during movement from one orbital to another.
  • English physicist Henry Moseley

    English physicist Henry Moseley provided atomic numbers, based on the number of electrons in an atom, rather than based on atomic mass.
  • James Chadwick

    James Chadwick first discovered neutrons, and isotopes were identified.
  • Glenn Seaborg

    Glenn Seaborg identified lanthanides and actinides.