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100
The First Elements
In the ancient times, prior to 1 A.D, there were nine elements known to man. They were gold, silver, copper, iron, lead, tin, mercury, sulfur, and carbon. These are elements that exist in pure form or that could be purified using relatively simple means. -
500
The European Dark Ages
A period of time for the Europeans when they lacked basic development whilst the other parts of the world were at a much quicker pace, reason being Roman Empire collapsing. -
Jan 1, 1000
The Arab Alchemists
Working during the Middle Ages, the Arab Alchemists were interested in turning base metals, such as lead, into gold. These early chemists wanted to turn one element into another by chemical means. However, they wasted their time. During chemical reactions, the atoms present in the elements are rearranged. Therefore, no new atoms, and thus, no new elements were formed. Instead, the Alchemists rather created different colours and pigments -
Jan 1, 1400
Rennaissance- End of the Dark Ages
During the 15th-16th Century, the colours and pigments created by the Alchemist were used by Artists. Such inspirational worked formed the "Reannaissancene and Humanism", the sole reason for the End of the Dark Ages. -
Discovery of Radioactivity
In the late 1800s, with the discovery of Radioactivy (involving contributions by a number of scientists), they realized that the nuclei of the atoms did change. One element could change into another in nuclear reactions, as opposed to the chemical, which only involve the electrons around the nucleas. -
The Periodic Table
Dmitri Mendeleev produced a table based on atomic weights but arranged 'periodically' with elements with similar properties under each other. His Periodic Table included the 66 known elements organized by atomic weights. -
Changing Models of the Atom- The Plum Pudding
Also known as the Chocolate Chip Cookie or Blueberry Muffin, J.J Thompson (who also discovered electrons in 1897), came up with such a theory in 1904. In this model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively charged "plums" surrounded by positively charged "pudding". Or simply, negatively charged "Chocolate chips/ Blueberries" surrounded by positivly charged "Cookies/ Muffins." -
Changing Models of the Atom- Rutherfords Atom
The Rutherford experiment, 1911, is a theory of a model of the atom devised by Ernest Rutherford, in which he shot alpha particles through a thin layer of gold foil. The model described the atom with a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated with the rest of the atom simply empty space. He suggested that the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun. -
Changing models of the Atom- Bohr's Atom
In 1913 Neil Bohr proposed his shell model of the atom to explain how electrons can have stable orbits around the nucleus. The motion of the electrons in the Rutherford model, however, was unstable. -
Enrico Fermi
In 1934, Enrico Fermi suggested how it should be possible to make new elements, with atoms larger than the heaviest naturally occurring atoms of Uranium (Atomic number-92). -
Atomic Bombings of Hiroshima and Nagasaki
At the end of the Second World War, as an aftermath of the horrific atomic bombs dropped on Japan, other new elements were identified. -
Man-Made Elements
Scientist working in America used Fermi's ideas. They bombarded large atoms with neutrons, which transformed into protons in the nuclei of the target atoms. Before 1955, they had made elements 94 to 101, 93, already being produced in 1940. -
Cold War
Dating from 1947 to 1991, the Cold War was the race between the US and Russia on the more technologically advanced country, whether it was the race to the moon, or the race to produce and therefore, name elements. nvolving many years of threats. -
The End to the Race to Name Elements
Russians soon became a nuclear power station and set up their own institutes to crete new elements with ever larger elements. Both countries the USA, and Russia created elements 102 to 106. However, arguments began on naming these elements. After many years of wrangling and debate- THE COLD WAR, the International Union of Pure and Applied Chemistry or IUPAC finally named the elements in 1997. -
Elements 107- 118
Germany soon joined the race to discover new elements. They managed tot get over the hurdle presented by element 107. They used heavy ion accelerator to smash nuclei together and successfully made the elements up to 110, taking 10 years to make the last. The final element- (118), Ununoctium was dicovered recently, in 2006
