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Jan 1, 1500
Democritus 460 BC
Lived from 460 BC to 370 BC and he created the idea that there were atoms that couldnt get smaller than an atom and were the building blocks of matter. -
Lavoisier Conservation of Mass Law
This law states that for any system closed to all transfers of matter and energy the mass of the system must remain constant over time, as system mass cannot change quantity if it is not added or removed. Lavoisier was born in 1743 and died in 1794 by execution. He was physcologicalist and was found guilty for adultry later in his life. -
Law of Definite Proportions
This law was first made by Joseph Proust, this law said that if an atom has the same number of atoms, it is always the same element. A bit about Proust, he was born in 1754 in France, and died in 1826 of an unkown cause. He lived in spain at one point but was forced by Napollen to move back to France where he lived the rest of his life and then died. -
Spherical Model
The date of its creation is unkown, but its a model of what was thought to be the atom at the time which was just a dense spherical shaped object. -
Dalton and Atomic Theory
John Dalton created the Atomic Theory with 4 major beliefs: all elements are made of tiny particals, all atoms of the same element are identical, compounds always have the same relative number and types of atoms, and chemical reactions are just rearrangement of atoms -
The life of Goldstein
Goldstein grew up in Poland for most of his life, he was born in 1850 and studied at Breslau for a lot of his time studying, the died in 1930 -
Albert Einstein
Einstein was born March 14th 1879 and was a geinues since birth. He performed several experiments, one was to prove the existance of atoms, he did this by putting cinnamon ontop of water, he noticed that the cinnamon moved even when no force was acting upon it, proving that something much smaller must be moving to create this motion. -
J,J, Thomson's Discovery of the Electron and Cathode
Thomson created a experiment that proved that there were even smaller particals that had a negative charge. The experiment envolved electricity being sent through a cathode ray tube and it caused the glass to glow, proving the electrions existance -
Quantum Mechanical Model
The Quantum Mechanical Model was created to represent the general location of electrons, this model was made by Erwin Schrodinger -
Plum Pudding Model
The Plum Pudding Model created by Thomson was the first model that shows positive and negative charges it was "positive pudding" that made the atom as a whole with the "negative eletrons" inside it. -
Gold Foil Experiment
In this experiment, Rutherford discovered that a nucleus exists in an atom by shooting alpha particals at gold foil and discovering that they were being deflected, the realized that this should only happen if its hitting a dense center which he later found out was the nucleus of the atom. -
Nuclear Model by Rutherford
The nuclear model contained the dense nucleus in the center and the always moving electrons and their paths around the nucleus. -
Bohr Model
This model shows the atom as a small positivly charged nucleus surrounded by negativly charged electrons. -
Niels Bohr
In 1913 Bohr agreed that electrons went around the nucleus, but not that they randomly moved but that they had circular motions around the nucleus which they followed. Niels was born in 1885 and died in 1962 to heart failure in his own home but won a nobel prize in 1922. -
Discovery of the Proton by Rutherford
Rutherford discovered the Proton in this year by doing an experiment where he fired alpha particals into nitrogen gas. Rutherford was born in New Zealand in 1871 and died of an unexpected death in 1937. -
Louis De Broglie
Louis proposed that moving particals, like electrons have some properties of waves and this idea -
Discovery of Neutron by Chadwick
Discovered uncharged particals also found in the nucleus called 'neutrons' Chadwick was born in 1891 and died in 1974 in his sleep. He worked on the Manhattan project and was a key scientist in the role of getting the atomic model we know today.
