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Period: 100 to
Atomic Models
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350
Plato 350 BC
Plato is known for the existence and uniqueness of the five regular solids, which are now known as the five "Platonic solids". It is not certain who first discovered these regular solids first, but many believe that it was spoke of as early as the Pythagoreans. -
400
The Alchemist 400bc
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430
Democritus 430 bc
This is the Greek philosopher Democritus who began the search for a description of matter more than 2400 years ago.
He asked could matter be divided into smaller and smaller pieces forever, or was there a limit to the number of times a piece of matter could be divided? -
robert boyle
Robert Boyle was most notably famous for his work in chemistry concerning the elemental nature of matter, as well as the relationship between the absolute pressure and volume of gas, which became known as Boyle's Law. Robert Boyle was also well known as a philosopher, inventor, physicist, and theologian.is known as “The Father of Chemistry” for his discovery that atoms must exist based on the relationship between pressure and volume of gas. His theorem called Boyle’s Law reasons. -
Lavoisier
The "father of modern chemistry", he was a French nobleman in the histories of chemistry and biology. He stated the first version of the law of conservation of mass, recognized and named oxygen, and hydrogen. He abolished the phlogiston theory and helped construct the metric system, He wrote the first extensive list of elements, and helped to reform chemical nomenclature. He discovered that, although matter may change its form or shape, its mass always remains the same. -
John Dalton 1803
John Dalton performed a number of experiments that eventually led to the acceptance of the idea of atoms. John deduced that all elements are composed of atoms. Atoms are indivisible and indestructible particles. -
Dmitri Mendeleev
Arranged elements into 7 groups with similar properties. He discovered that the properties of elements "were periodic functions of the their atomic weights". This became known as the Periodic Law -
J.J Thompson 1897
English scientist J.J. Thomson provided the first hint that an atom is made of even smaller particles.Thomson studied the passage of an electric current through a gas. -
Marie Curie
Studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre also discovered the radioactive elements polonium and radium -
Albert Einstein
he was known for his contributions to the quantam theory. -
Rutherford’s Gold Foil Experiment 1908
In 1908, the English physicist Ernest Rutherford was hard at work on an experiment that seemed to have little to do with unraveling the mysteries of the atomic structure.
Rutherford’s experiment Involved firing a stream of tiny positively charged particles at a thin sheet of gold foil (2000 atoms thick) -
Bohr Model 1913
In his model, he placed each electron in a specific energy level. According to Bohr’s atomic model, electrons move in definite orbits around the nucleus, much like planets circle the sun. -
Henry G. J. Mosely
Using x-ray tubes, determined the charges on the nuclei of most atoms. He wrote"The atomic number of an element is equal to the number of protons in the nucleus". This work was used to reorganize the periodic table based upon atomic number instead of atomic mass.
