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Antoine Lavoisier
Lavoisier is known as the modern father of chemistry. He established the law of conservation of mass which states matter can be neither created nor destroyed. He tested the Phlogiston theory and was able to disprove it. Lavoisier came up with the system of chemical nomenclature which is still used today. He wrote a book about chemistry which contained a list of elements that could not be broken down. Lavoisier believed that the existence of atoms was impossible. -
Joseph Proust
He published the law of definite proportions which says that compounds have the same proportions of their elements by weight. This helped Dalton with his atomic theory. -
John Dalton
Dalton is most famously known for his atomic theory. He stated that atoms could be neither created nor destroyed and also studied the atomic weight of many atoms. He said atoms of different elements could be universally distinguished because of their atomic weight. He proved that atoms combine in similar ratios. He also wrote down the atomic weight of every known element. -
William Crookes
He discovered the principle of Crooke’s radiometer which is a device that converts light radiation into rotary motion. He discovered the element thallium. He demonstrated how cathode rays travel in straight lines. -
Max Planck
Planck studied thermodynamics which helped him come up with his quantum theory. He proposed that energy is radiated not continuously but every minute. It is used to describe the behavior of particles on the atomic scale. He announced his findings in 1900. Einstein used his theory to describe the particle properties of light. He won the Nobel Peace prize for his research in 1918. -
JJ Thomson
Thomson studied cathode rays which are beams of light that follow an electrical charge in a vacuum. Using these rays he was able to find the ratio of the electrical charge to the mass of the particle and found the ratios were the same no matter what gas was used. This led him to discover that the particles that make the gasses are universal. He discovered that matter is made up of particles smaller than atoms called electrons. He proved the existence of isotopes by finding that neon had two. -
Marie Curie
She studied many radioactive materials. She found that uranium ore was more radioactive than the uranium extracted from it. She found the existence of two new radioactive elements the first she named polonium and the second was radium. She was awarded the Nobel Peace Prize in 1903 and was the first woman to ever receive it. -
Quantum Theory discovered
Max Planck discovered it in 1900 -
Plum Pudding Theory
JJ Thomson came up with it after he found the electron. -
Albert Einstein
He proved the existence of atoms using an ordinary microscope. In 1905 he published his theory of relativity. He also said that light can only be absorbed or emitted in quanta. All of this work earned him the Nobel Peace prize. Einstein was able to prove the existence of atoms by doing calculations. He wrote a letter to President Roosevelt stating that atom bombs should be used in World War 2. -
Neils Bohr
Bohr worked under Rutherford in the beginning of his career where he started studying the properties of the atom. He combined Rutherford’s information about the nucleus and Planck’s quantum theory to show what happens inside the atom. This earned him the Nobel Peace Prize in 1922. He discovered that electrons travel in separate orbitals. Bohr’s atomic model shows a nucleus surrounded by electrons orbiting. -
Ernie Rutherford
He discovered the nucleus by shooting alpha particles through gold foil and noticed that some of the particles bounced off but most of them went through. He constructed his model of the atom. In his model there is a nucleus that contains all the mass in the atom. The nucleus is positively charged and is surrounded by negatively particles called electrons. He also discovered the proton. -
Nucleus Discovered
It was discovered by Rutherford when he shot alpha particles and they bouced back. -
Beginning of WW1
Many of the Scientist went to go fight in the war. -
The first atom is split
First atom is split by Rutherford -
Louis de Broglie
Broglie worked with his brother Maurice on X-rays which helped him come up with his award winning theory on electron waves. His theory helped develop wave mechanics. His theory offered an answer to how electrons move throughout an atom. The theory was later proved by a group of scientist in 1927 which ended up winning him the Nobel Peace prize. -
WW1 ends
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Hitler rises to power
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Werner Heisenberg
In 1924 he worked with Neils Bohr. He made his theory of quantum mechanics which helped with the discovery of allotropic forms of hydrogen. He also said you cannot predict or see a electron in a given spot in an orbital at a given time. His principle of uncertainty stated that a mobile particle’s position cannot be determined without error. He earned the Nobel Peace Prize in 1932. -
Friedrich Hund
Hund made many contributions to the quantum theory. He has rules called Hund’s rules which have to do with electron configurations. He helped form electron orbitals. He also helped the electron structure of molecules and chemical formations by using orbitals. He also discovered the tunnel effect or otherwise known as quantum tunneling. -
Erwin Schrodinger
He used Bohr’s model to make his own model that can predict the odds of the location of an electron. He used mathematical equations to calculate the odds of finding an electron in a certain location. He also made a Wave calculation that calculates the exact energy level of an atom. -
James Chadwick
James Chadwick discovered the neutron. There was unexplained mass left over so he tried to find the third particle. He shot particles at boron and measure the velocity of the protons that flew out. He was then able to determine the mass of the third particle the neutron. He won the Nobel Peace prize for his work. -
Discovery of Nuclear Fission
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Beginning of WW2
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End of WW2
It is dropped over Japan. -
Atomic bomb is dropped
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Murray Gell-Mann
He showed scientists what make up protons and neutrons which is quarks. Every proton and neutron contains 3 quarks. He won the Nobel Peace PRize for his discovery.
