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Period: Jan 1, 1000 to
Timeline of Matter
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Sep 23, 1101
The Stone Age - 8000B.C.
Middle Eastern people used tools made out of stone. Using the tools they discovered, they created fire which led to the production of glass and ceramic material. Although, metals had not been discovered yet. -
Sep 23, 1102
Discovery of Metals - 4000B.C.
Early chemists have discovered metals such as gold and copper. The metals have been known to be highly valuable because it could be shaped into useful tools to Human beings. -
Sep 30, 1103
The Iron Age - 1200B.C.
The people from the Middle East, Hittites, have learned how to mine iron from rocks and turn it into useful tools. This led to the discovery of still as well. They also experimented and combined different types of liquids to create new ones. -
Sep 23, 1104
Democritus' Theory - 400B.C.
Democritus, a Greek philosopher used the term, '"atomos" to describe small particles that could not be broken down any further. He said that each type of material was made out of "atomos". These materials were said to hold a set of unique properties and when combined, can create newer materials with their own unique properties. -
Sep 23, 1105
Aristotle's Theory - 350B.C.
Another Greek philosopher, Aristotle stated that everything was made out of four elements which were Earth, Wind, Fire and Water. His description was preffered over Democritus' for 2000 years because he was well known and respected. -
Robert Boyle's Theory of Matter
People became more like scientists and took interest in the nature of matter, one such as Robert Boyle who was interested in the behaviour of gas and determining it's composition. He became convinced that matter was made out of tiny particles and felt that the purpose of chemistry was to determine the types of particles that make up each substance. -
Dalton's Theory of the Atomic Structure
English scientist, John Dalton developed his own thoery on the composition of matter stating that mattter is made out of elements. He put forward the first modern thoery of the atomic structure stating that each element is made out of atoms. -
The Raisin Bun Model
British physicist, J.J. Thomson, proposed the "raisin bun" model of the atom which describes the atom as a positively charged sphere in which electrons are embedded in. The negative electrons were said to balance the positive sphere, so the whole atom has no electrical charge. -
Rutherford's Atomic Model
Rutherford conducted experiments using Thomson's model of the atom and proposed a new model. He suggested that atoms were mainly empty space through which positive particles could pass. There was a positively charged core to which he called the "nucleus" and calculated that it was only about 1/10,000th the size of the atom. -
Modern Atomic Model
Danish researcher, Niels Bohr who worked with Rutherford suggested that electrons do not orbit randomly in the atom. He stated that they move in specific circular orbits called "electron shells". He believed that electrons jump between these shells by gaining or losing energy. Today, scientists still refer to Bohr's model.
