-
Thales thinks differently from other philosophers. He makes his theories from observations, not myths or legends.
He thinks the whole world is made of water. -
Anaximenes (Thales’ student), disagrees with Thales’ idea about the world being made of water. He insisted the world was made of air, since air was all around them. -
Democritus insists that something could be cut so small to a limit, which he called ‘atomos’, which meant unbreakable. -
Scientist were unable to agree with Democritus’ creative thought (even though it was pretty accurate), and later Aristotle put forward the idea that everything was of any one of the four elements; water, air, fire, and earth. -
Antoine Lavoisier and his wife Marie-Anne, investigated the changes which occurred when two chemicals reacted with each other. Lavoisier found that the total mass of the chemicals was equal to the product created after the reaction. Now, from this new information, Lavoisier put forward a law called ‘the law of conservation of mass’, which stated that matter could not be created nor destroyed. -
Proust agrees with Lavoisier about the conservation of mass after testing it out himself. -
John Dalton says that
1) all matter is composed of tiny particles called atoms
2) Atoms cannot be divided into smaller particles
3) Atoms of an element all have the same mass and properties.
4) the atoms of different elements have different masses and different properties.
5) Atoms combine in simple whole numbers when they from compounds. -
William Prout studied the masses of all the different atoms of elements.
-
JJ Thompson discovers electrons, but calls them corpuscles, using a cathode ray tube, also known as Crook’s tube.
-
Ernest Rutherford works on JJ Thompson’s theory.
He tests the theory with the gold sheet experiment.