-
Aristotle discovered the main elements were fire, water, earth and air
-
Alchemist used a variety of symbols to identify each element and made many different discoveries to the modern science of chemistry.
e.g. gold (the picture on the left) -
Lavoiser found that mass is conserved in a chemical reaction
-
He was best know for the discovery of the law of constant composition which he stated that chemical compounds always combine in constant proportions.
-
John Dalton created the very first atomic theory he viewed atoms as tiny, solid balls and had 4 statements for the atomic theory which were: atoms are tiny, invisible particles, atoms of one element are all the same, atoms of different elements are different and compounds form by combining atoms.
-
He discovered electrons and was the first scientist to show that the atom was made of even smaller things. He also proposed the existece of positive particles.
-
He showed that atoms have positive particles in the centre and are mostly empty space, these positive particles are called protons and the centre of the atom is called the nucleus.
-
Chadwick discovered the neutrons he was working with Ernest Rutherford and found out that particles with no charge were called neutrons which were located in the nucleus.
You are not authorized to access this page.