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Democritus creates the first atomic theory
Democritus believed that The universe is composed of two elements: the atoms and the void.
the atomic theory stated that
1.all matter consist of invisible paticles known as atoms
2.atoms are indivisible
3.atoms are indestructable -
isaac newton's mechanical universe concept
Newton created a concept that the mechanical universe, due to the laws of motion is made up of small solid masses in motion aka atoms. -
jhon dalton revises the atomic theory and proposes an atomic model
dalton created the first atomic model which looked like one spherical mass. Daltons atomic theory consisted of four major ideas
1 all elements are composed of atoms
2 atoms are only similar to that of their own element
3 atoms of diffrent elements can phisically and chemically combine into whole number ratios
4 chemical reactions occur when atoms are seperated joined or rearranged. -
William Crookes cathode ray experiment
through Williams experiment he had found that cathode rays are negatively charged. -
George jhonstone stoney concept of electron
Stoney created the concept that atoms contain even smaller particles that have a charge. he also pointed out that atoms give off an electric charge thus concieving the thought of electrons. -
Wilhelm Roentgen discovers x rays
penetrating rays coming from the CRT that were not deflected by a magnetic field. He named them "X-rays" -
J.J thomson confirms electrons in atoms
J.J Thomson, while using a electric feild to diflect the beams in a cathode ray discovered that their must be a negative charge in the ray therfore confirming electrons within the atoms of the ray. also presents his plum pudding atomic model. -
max planck discovers the base line of the quantum theory
planck came up with the thoery that atoms do not behave in the way we precieve this theory is known as quantum theory that do not follow regular human scaled physics so well. -
hantaro nagaota presents the firstorbiting electron model
proposes a model depicting rings of electrons revolving around a positively charged particle. although it was wrong it opened a new thought of revolving electrons -
Albert Einstein creates the equation E=mc squared
E=mc squared was einsteins trademark equation stating that energy equals mass times the velocity of light squared. later on einstein helped the allies win WW2 through his assistance in the manhattan prodject. -
rutherfords gold foil experiment
during his goldfoil experiment he found that an atom has a small positively charged nucleus, also the atom was mostly empty space depicting the electrons orbiting the nucleus in a random fashinon. -
HGJ Mosely uses atomic number to allign the periodic table
Used x-ray tubes, determined the charges of an atoms nucleus. 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. -
Neils Bohr
Developed an explanation of atomic structure that shows electrons do not randomly move around in the atom in a random way this was known as the electrons orbital. -
Erwin Schrodinger
Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom. -
The Quantum Mechanical Model
this is the most upto date model of an atom to date this depicts the orbitals of electrons around a nucleus and gives us a better understanding of an atom it also shows diffrent energy levels and clouds where electrons are most likely found. -
James Chadwick
Using alpha particles, he discovered a neutral particle with a mass close to that of a proton this is now known as a neutron. -
Lise Meitner, Hahn , Strassman discover what causes fission
large elements capture neutrons and then become unstable causing a chain reaction that gives off neutrons thus causing the reaction to continue. -
atomic distruction
the first atomic bomb is dropped on japan killing hundreds of thousands jappanese the next day anotherone wasused on nagasaki thus ending the war.
