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Democritus
Democritus was the first person to purpose the idea that matter wasn't infinitely divisible in 300 B.C. -
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Aristotle
In 348 BC, Aristotle rejected the atomic theory entirely because it didn't agree with his own ideas in nature. One of Aristotle's major criticisms concerned the idea that atoms moved through empty space. -
Joseph Proust
Joseph proved that the relative quantities of any given pure chemical compound constituent elements remain invariant, reguardless of the compound source. This is the Law of Definite Proportions. -
Antonie Lavosier
Antonie Lavosier complied a list of 23 elements. Today, they're part of the periodic table. Some of the elements have been known since prehistoric times like silver, gold, carbon, and oxygen. -
John Dalton
Explanation of the Atomic Theory John Dalton is responsible for inventing the atomic theory in 1803. He came up with 5 statements that make up the atomic theory. -
Amedeo Avogadro
The mole is the SI base unit used to measure the amount of a substance. It is the number of representative particles, carbon atoms, in exactly 12 g of pure carbon-12. It has been figured that a mole of anything contains 6.022 136 7 x 10 to the 23rd representative particles. The large number above is known as Avogadro's number, in honor of Amedeo who determined the volume of one mole of a gas. -
William Crookes
William Crookes and other scientists wanted to know if their was an electric charge between matter and an electric charge. Crookes passed electricity through glass tubes known as cathode ray tubes, which most of the air had been removed. He noticed a flash of light in one of the tubes. It was produced by some sort of radiation striking a light-producing coating that was applied at the end of the tube. This discovery led to the inventions of the television and the computer screen. -
J.J Thomson
Nobody had determined the mass of a single cathode ray particle, until J.J. Thomson. Unable to measure the particle's mass directly, Thomson began many cathode ray tube experiments to determine the ratio of charge to its mass. -
Henri Becquerel
In 1895, Becquerel was studying minerals that emit light after being exposed to sunlight, a phenomenon called phosphorescence. Becquerel accidentally discovered that phosphorescent uranium salts, even when not exposed to light, produced spontaneous emissions that darkened photographic plates. -
Marie Curie
Marie Curie discovery video Marie Curie took Becquerel's mineral sample and isolated the componets emitting the rays. Marie and her husband, Pierre, concluded that the darkening of the photographic plates was due to rays emitted specifically from the uranium atoms present in the mineral sample. -
Max Planck
Max Planck concluded that Matter can gain or lose energy only in small, specific amounts called quanta. -
Albert Einstein
E=MC2 explained Einstein created one of the most famous theories ever that showed a relationship between mass and energy. The formula says energy equals mass times the speed of light squared. (E=MC2) -
1906 San Francisco Earthquake
This earthquake back in 1906 was the largest ever recorded in San Francisco, with a magnitude of 7.9. 3,000 people were killed and there was not much warning as the earthquake struck at 5:12 am. -
Robert Millikan
The Charge of an Electron Experiment Robert Millikan was the one responsible for determining the charge of an electron. -
Henry Moseley
Henry Moseley discovered that atoms of each element contain a unique positive charge in their nuclei in the early 1900's. -
Ernest Rutherford
Ernest Rutherford and a group of scientiests discoved that alpha particles could be deflected at very large angles. Ernest was the one who wanted to conduct the experiment after beginning to study alpha particles. In 1920, Rutherford refined the concept of the nucleus. -
Niels Bohr
Bohr proposed a model of the hydrogen atom. Bohhr's model also correctly predicted the frequencies of the lines in the hydrogen's atomic emission spectrum. -
WWI
Short Recap of World War One World War One began on July 28th, 1914 and ended on November 18th, 1918. It was also known as the first world war. USA was part of the Allied Powers, which was the winning side of the war. -
Louis de Brogile
Louis de Brogile came up with his own equation which is known as the de Brogile equation. He derived the equation for the wavelength of a particle of mass moving at velocity. -
Erwin Schrodinger
Schrodinger derived an equation that treated the hydrogen atom's electron as a wave. His new model for the hydrogen atom seemed to apply equally well to atoms of other elements, an area in which Bohr's model failed. -
James Chadwick
Neutrons James Chadwick was responsible for showing that the nucleus had a neutron. It was a mass nearly equal to a proton, but has no electrical charge. -
Werner Heisenberg
Heisenberg concluded that it is impossible to make any measurement on an object without disturbing the object first. -
World War Two
World War Two began on September 1st, 1939 and ended September 2nd, 1945. USA was on the winning side. -
The First Ever Super Bowl
The very first ever Super Bowl was played on January 15th, 1967 between the Green Bay Packers and the Kansas City Chiefs. The Packers head coach, Vince Lombardi, and the team made history as the first ever team to win the Super Bowl. -
The Chicago Bears win the Super Bowl
The Chicago Bears won their first and only Super Bowl back in 1985 under head coach, Mike Ditka. The Bears defeated the New England Patriots. -
World Trade Center
The attack on 9/11 is one of the worst attacks to ever take place in America. Two planes driven by terrorists collided into the World Trade Center buildings back in 2001. Around 3,000 people were killed. -
Hurricane Katrina
Hurricane Katrina was the most devestating hurricane to strike the United States. At least 1,833 people were killed, and you could probably imagine that the hurrican was a category 5. Winds reached 175 mph. -
Parkersburg Tornado
On May 25th, 2008 at 4:59 PM, Parkersburg, Iowa took a huge hit from an EF5 tornado that killled six people. Winds reached speeds of 205 mph. People all across the country donated and help with recovery efforts after the big tornado struck. -
Sandy Hook Shooting
On December 14th, 2012, Adam Lanza lost his mind when he opened fire inside the walls of the Sandy Hook Elementary School in Newton, Conneticut. He fatally shot more the 30 kids and teachers. -
Philippines Typhoon
Around 4,000 people were killed and 18,500 were injured just a few months ago when the largest typhoon to ever hit the Philippines swept through, taking out everything in its path. People from all over the world are donating to help the ones affected.
