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The Start of The Middle Ages
The Middle Ages in Europe were called the "Dark Ages" because of the lack of scientific devolpment at that time. -
400
Alchemists in the Middle Ages
Most alchemists in the Middle Ages were obsessed with trying to turn base metals, such as lead into gold. It never really worked though. In chemical reactions the atoms of elements present are rearranged. No new atoms are ever made. -
Sep 19, 1500
The Renaissance
The Renaissance was the end of the Dark Ages. Europe finally started to develop. -
Phosphorus
Hennig Brand discovered phosphorus in 1669 -
Discovery of Element 1 - Hydrogen
Hydrogen was discovered by Henry Cavendish in 1766. -
Nitrogen
Nitrogen was discovered by Daniel Rutherford 1772. -
Oxygen
Joseph Priestly discovered oxygen in 1774 and published his findings the same year, three years before Carl Wilhelm Scheele published. -
Chlorine
Chlorine was discovered in 1774 by Carl Helm Scheele. -
Magnesium
Magnesium was recognized as an element by Joseph Black in 1775. -
Magnesium
Magnesium was recognized as an element by Joseph Black in 1775. -
Discovery of Element 4 - Beryllium
Beryllium was discovered in 1798 by Louis Nicolas Vauquelin. -
Nuclei of atoms do change!
In the late 1800s, scientists realized that the nuclei of atoms did change! One element can change into another in a nuclear reaction, the opposite of a chemical reaction which involves electrons around the nucleus. -
Sodium
Sodium was discovered by Humphrey Davy in 1807. -
Discovery of Element 5 - Boron
Boron was discovered by Joseph Louis Gay-Lussac and Louis Jacques Thénard in 1808. -
Discovery of Element 3 - Lithuim
Lithium is the third element on the periodic table and it was discovered by Johan Arfvedson 1817. -
Silicon
Jöns Jacob Berzelius discovered the element Silicon in 1824. -
Aluminium
Aluminium was discovered by Friedrich Wöhler in 1827. -
Fluorine
Fluorine was discovered by Henri Moissan in 1866. -
Discovery of Element 2 - Helium
Helium was discovered in 1868 by Pierre Janssen 1868. -
Argon
Argon was discovered by Lord Rayleigh and William Ramsay in 1894. -
The Plum Pudding Model
The Plum Pudding Model was invented by J.J Thompson in 1897. He came up with the atomic structure theory, where all parts of the atom are positive recharge. -
Neon
William Ramsay and Morris Travers discovered Neon in 1898 -
Bohr's Atom
In 1913, Niels Bohr organized the electrons into shells, now called orbitals. -
Enrico Fermi - Famous Alchemist
Enrico Fermi was a pioneer in the search of new elements. In 1934, he suggested how it should be possible to make new elements, with atoms larger than the heaviest naturally occurring atoms of uranium. -
New elements discovered
In 1940, element 93 was produced. At that time, it was the end of the Second World War and due to all nuclear bombs dropped on Japan, new elements were identified. -
Elements 94 - 101 were produced
Soon, other countries started using Fermi's ideas! They bombarded large atoms with neutrons, which transformed into protons in the nuclei of the target of atoms. Before 1955, they had made elements 94 - 101. -
Naming the elements
Because of the arguments between Russia and USA of what name ot give to the new elements found, IUPAC ( International Union of Pure and Applied Chemistry) finally interfered naming elements 94 - 101. -
Rutherfords Atom
Earnest Rutherford shot alpha particles through a thin layer of gold foil and he found out three things.
1. Most of the particles went right through showing that nearly all of the atoms were empty space.
2. Some electrons bounced back at wide angles, showing that the center of an atom does have a nucleus.
3. Some electrons were bounced right back meaning showing that nearly all of the mass of the atom was at the nucleus/ center.