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500 BCE
The Alchemists
The Alchemists were a group of scholars who existed between 500 B.C and 1720. They were known for trying to make a potion that would help them live forever. This would lead to their other major discovery, which is the Scientific Method. -
430 BCE
Democritus
Democritus was a Greek philosopher who believed that atoms were incompressible and indestructible. He also said that atoms moved infinitely through empty space until they were stopped. He also gave the word "atomos", which is now called atoms. -
427 BCE
Plato
Plato was a Greek philosopher who made the atomic theory in 427 B.C, which stated that atoms are served by ideal geometrical forms. -
Robert Boyle
Robert Boyle was an Irish philosopher who found that, in 1662, the volume of a gas decreases when pressure increases. This would come to be known as Boyle's Law. -
Antoine Lavoisier
Antoine Lavoisier was a French chemist who created the first version of the Law of Conservation of Matter. Antoine Lavoisier also named the element Oxygen in 1778, and Hydrogen in 1783. Thirdly, Lavoisier made the first ever periodic table, which would be improved by Dmitri Mendeleev. -
The Billiard Ball Model
The Billiard Ball Model was made by John Dalton in 1803. -
John Dalton
John Dalton was an English chemist who was known for creating his atomic theory in 1808, which stated that all matter was composed of atoms. Dalton also found atomic weight, as well as right chemical symbols. -
Amedeo Avogadro
Amedeo Avogadro was an Italian scientist who created Avogadro's number, which is the number of elementary particles per mole of a substance. The number is 6.023 x 10^23 -
Dmitri Mendeleev
Dmitri Mendeleev was a Russian chemist who is best known for arranging all the elements based on their atomic weight onto a table. This table is now known as the Periodic Table of Elements. -
JJ Thompson
JJ Thompson was a British physicist who found electrons and subatomic particles in 1897. Thompson found the electrons on accident while working with glass tubes. Thompson also, in 1904, would make the Plum Pudding Model. -
Pierre and Marie Curie
Pierre Curie was a French physicist, and Marie Curie was a Polish-French physicist. The couple were known for finding the elements radium and polonium in 1898, and radium poisoning would lead to Marie's death in 1934. Pierre also made the statement that atoms might be made of smaller things. -
Plum Pudding Model
The Plum Pudding Model was created in 1904 by JJ Thompson. -
Albert Einstein
Albert Einstein was a German physicist who found that nature and matter combine somehow. He also helped push electrons into quantum physics in 1905. -
Robert Millikan
Robert Millikan was an American physicist who helped determine the electric charge carried by a single electron in 1909. He also conducted the famous Oil Drop experiment, which was used to find the electric charge of the electron. -
Ernest Rutherford
Ernest Rutherford was a New Zealand physicist who found the atomic nucleus using other research from other scientists and physicists. He did this by doing the Rutherford experiment, which helped show that an atom was just an empty space except for a tiny nucleus. -
Solar System Model
The Solar System Model was made by Niels Bohr in 1913. -
Niels Bohr
Niels Bohr was a Danish physicist who created the Bohr model for atomic hydrogen in 1913. Bohr also created the theory for hydrogen atom. Bohr also discovered that electrons orbit the nucleus of an atom. -
Henry G.J Mosely
Henry G.J Mosely was an English physicist who is know for making the atomic number, which is the positive charges in a nucleus. He also established that there are 3 unknown elements, numbers 43, 61 and 75. -
Electron Cloud Model
The Electron Cloud Model was created by Erwin Schrodinger in 1926 -
Werner Heisenberg
Werner Heisenberg was a German physicist who contributed to atomic theory through quantum mechanics in 1927. Heisenberg also discovered the uncertainty principle, which stated that the position and velocity of an object cannot both be measured exactly. -
James Chadwick
James Chadwick was a British physicist who found the existence of the neutron in 1932. Chadwick also helped in the creation of the atomic bomb in that same year. -
Erwin Schrodinger
Erwin Schrodinger was an Austrian-Irish physicist who did the experiment known as Schrodinger's Cat, which states that an atom can decay something, but it also might not. You do not know what will happen. So, in this instance, Schrodinger put a cat in a box, and through this process, the cat was both simultaneously dead and alive.
