Theories of Matter Throughout History

*The first chemists lived before 8000 B.C in an area now called the Middle East.
*This period is known as the Stone Age because humans only used simple stone tools at the time.
*Metals had not been discovered yet
*These chemists learned how to start and control fire, resulting in being able to change the range of substances to their advantage.

*Early chemists investigated only materials that had high value to humans
*Metals such as gold and copper
*Copper could be used to make pots, coins, tools and jewellery
*Discovered that when copper is heated it becomes very useful because it can be rolled into sheets or be stretched into long wires
*Gold could be made into detailed designs, formed into wire, beat into sheets, and could not be made into weapons

*Experimentation with copper around 4500 B.C led to the creation of hard, strong material known as bronze, which is produces when copper and tin are heated together
*Many cultures investigated in ways of extracting and using different types of liquids
*Juices and oils were especially important both in everyday life and in rituals

*Around 1200 B.C a group of people in the Middle East called Hittites discovered how to extract iron from rocks and turn it into a useful material
*Chemists learned to combine iron with carbon to produce an even harder and stronger material, steel
*Steel could be used to make sharper blades that could be fashioned for hunting
*Steel could be used to build stronger armour to protect soldiers in battle

*Democritus used the word 'atomos' to describe the smallest particles that could not be broken down any further
*Atomos means 'indivisible'
*He stated that each type of material was made up of different types of 'atomos'
*He believed these different particles gave each material its own set of unique properties, and by mixing different 'atomos' you could make different materials with their own unique properties

*Ideas that all matter is made up of particles started
*Greek philosophers observed that a rock could be broken into smaller and smaller pieces until it became a powder
*Greek philosophers wondered how many times you could break the particles of powder down until they couldn't be broken down any more

*For about 2000 years after Democritus's time, experiments with matter were mainly carried out by alchemists, people who believed it should be possible to change metal into gold
*Alchemy - Arabic word al-kimiya, translates to "the chemist"
*Alchemy is considered a pseudo-science, not real science, because it includes the use of 'magic'
*During this time, although alchemy isn't considered a science, many useful tools were developed that we use in labs today, and other practical discoveries were made as well:
-beakers and filters
-plaster of Paris
-how to prepare chemicals such as hydrochloric acid
*Andreas Libau, a German alchemist, published Alchemia, the first chemistry text ever printed

*Aristotle stated that everything was made up of earth, air, fire, and water
*Since Aristotle was well known and well respected, his description of matter was preferred over that of Democritus for about 2000 years

*Experimented with the behaviour of gasses
*Interested in what happened when gasses were put under pressure as well as determining the composition of gasses and other substances
*Convinced that matter was made up of tiny particles, group together in different ways to form individual substances, similar to the beliefs of Democritus
*Felt the purpose of chemistry was to determine the types of particles each substance was made up of

*Studied chemical interactions
*Developed a system for naming chemicals
*Defined some of the substances discovered to his time, including hydrogen, oxygen, and carbon
*Called the "Father of Modern Chemistry"
*After his execution, his wife Marie, who had previously worked as his lab assistant, continued his work