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Period: 300 to
Atomic History Timeline
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460
Democritus 460-370 BC
Discovered that matter is made up of atoms. Atoms are forever and can't be seen cause they are invisible, they are so small that they can't be divided any smaller. -
460
Democritus model
Atoms are different texture and shape for each element. -
Oct 4, 1452
Idea of a parachute
The ideas of a parachute are sketched outby Leonardo Da Vinci. -
John Dalton 1766-1844
Changed Democritus's idea on atoms into a scientific theory. Atoms of an element are indentical. Atoms of different elements can combine which is then a compound. Chemical reactions occur when atoms are seperated, joined or rearagned. -
Parachute constructed
The first parachute is made. -
Joseph Proust
He discovered the law of definite proportions, also known as Proust's law, which states that in any compound the elements are present in a fixed proportion by weight. -
Dalton Model
John Dalton's model of the atom is a tiny but indestructable particles with no internal structure. -
Robert Milikan 1868-1953
Discoverd how to find the electron charge and mass. -
Henri Becquerel
He discovered atoms have radio activity, Some have more than others. -
J.J. Thompson
Discoeverd that the electron has negative charges, and there must be positive charges somewhere for matter to be nuetral. He also invented the Plum Pudding Model. -
Plum Pudding Model
Electrons were stuck into a lump of positive charge, similar to raisin dough, The electrons were identified as plums and the mixture they were in was indentified as pudding. -
Max Planck
He discovered a way to calculate the energy of a photon. He started the invention of the Quantum theory. -
Ernest Rutherford
Wins the Noble Peace Prize -
Ernest Rutherford
Discovers the nucleus. The middle of the atom is empty space and all positive charged atoms account for the mass of the atom. -
Rutherford Model
There is a nucleus in the middle with electrons forming a cloud around it. -
Neils Bohr
He discovered that electrons move in circualr orbits with a common distance from the nucleus. Created a model called Bohr Model. -
Bohr Model
The nucleus is in the middle and the electrons orbit it with fixed distances. -
Automobile
The automobile becomes a very popular demand for people -
Louis de Broglie
He thinks moving particles like electrons have some properties in common with waves. -
Erwin Schrodinger
He explained the motion of electrons in atoms with a mathematical equation. This later leads to the electron cloud formula. -
Werner Heisenberg
Founder of quantum machanics, the physics of the atomis world. He also discovered the uncerntain principle of the quantum theory. -
Quantum Mechanical Model
This is the latest model and the one we go by today. -
Amelia Earhart
She was the first women to fly across the Atlantic -
James Chadwick
Confirms that neutrons exist and are neutral. Neutrons are in the Atomic nuclei along with the positively charged protons. -
World War II begins
The second world war begins against Germany -
World War II
The second World War is finally over -
Slinky
The first slinky is invented by Betty and Richard James -
Glue Stick
The Glue stick is invented by a German company called Henkel -
Invention of cell phonw
Martin Cooper invented the cell phone which is very popular today. -
Music Videos
MTV shows music videos for the first time. -
September 11
The twin towers are hit with planes in a terrorist attack -
Aristotle 384/322 BC
He decided that all substances are made up of four basic constitutions, dryness, wetness, heat and cold.
