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2470 BCE
The Great Pyramid of Giza was built
The construction for the Great Pyramid of Giza began. This pyramids was on of the many great engineering feats by the Ancient Egyptians. -
498 BCE
Democritus
His idea was that atoms are solid, homogeneous, indestructible, and invisible. His ideas were eventually rejected because other philosophers had questions that he couldn't answer. -
402 BCE
Aristotle
He rejected the atomic "theory" entirely because it did not agree with his own ideas on nature. -
The United States Declared Independence
The Declaration of Independence was signed on this day to become free from the British Monarchy. It also celebrates the birth of American Independence. -
Antonie Lavosier
He performed experiments and came up with the law of conservation: matter cannot be destroyed or created. -
Joseph Proust
He came up with the Law of Definite Proportions (a compound is made of the same ratio of elements). -
John Dalton
Dalton's Atomic Theory: all matter is made of small particles called atoms; all atoms of a certain element are identical; atoms can't be created, divided, or destroyed; and in chemical reactions, atoms are separated, combined, or rearranged. His theory explains the conservation of mass. -
Amadeo Avagadro
He thought that "equal volumes of all gases at the same temperature and pressure contain equal numbers of molecules". He also found out that elements could exist as molecules instead of individual atoms. -
William Crookes
English physicist who accidentally discovered the cathode ray. This led to the invention of the television. -
Eiffel Tower was built
The construction of the Eiffel Tower was completed. -
Henri Becquerel
He studied phosphorescence and discovered spontaneous radioactivity -
Madame Curie
She discovered two new elements: polium and radium. She studied radioactivity and came up with the term radiation. She also established the field of nuclear chemistry -
J.J. Thomson
Came up with a model of the atom know as the "Plum Pudding Model" to answer questions about electrons in atoms. -
Max Planck
He discovered that matter can only gain or lose energy in small, specific amounts. These amounts were called quanta. -
Australia became a country
Australia became an independent nation and the Commonwealth of Australia became a constitutional monarchy. -
Albert Einstein
He suggested that electromagnetic radiation is both wavelike and particle-like. He also proposed that the energy of a photon of light must have a minimum. -
Robert Millikan
Determined the charge of a single electron and also calculated its mass. -
Ernest Rutherford
Discovered that the "Plum Pudding Model" was incorrect based on his experimentations with alpha particles and gold foil. His experiment also explained why most matter is neutral: the positive charges in the nucleus balance the negative charges of electrons. These positively charged particles would be called protons. -
Niels Bohr
He tried to understand the movements of electrons. He suggested that when a hydrogen atom is in the ground state, it doesn't radiate any energy. As energy is added, the electron moves into a higher-energy orbit. This explained hydrogen's "spectral lines", but couldn't explain any other element. His idea did help make the groundwork for other atomic models. -
WWI Began
Archduke Franz Ferdinand (heir to the Austro-Hungary Empire) was killed by Garvilo Princip (a Serbian nationalist). This assasinatino set off a chain of events that started the Great War and later, World War 1. Video Link: http://www.history.com/topics/world-war-i/outbreak-of-world-war-i -
Henry Moseley
Discovered that atoms contain a unique positive charge in their nucleus. And that these protons identify it as a specific element. -
Louis deBroglie
He created an equation to predict the movements of electrons based on his conclusion that electrons behave like waves. -
Werner Heisenberg
He thought that it would be impossible to measure an object without disturbing the object. This could be used when trying to locate the location of an electron. -
Erwin Schrodinger
He worked more on the wave-particle theory. In his equation he treated the electrons of hydrogen atoms as a wave. This model worked for other elements too. This equation is called the "quantum mechanical model of the atom". -
James Chadwick
Discovered that the nucleus contained a particle called a neutron. It carries no electric charge. -
WWII ended
President Truman authorized the use of atomic bombs on Hiroshima and Nagasaki in Japan. Then Japan accepts the terms of the Potsdam Declaration and finally General Douglas MacArthur accepts Japan's surrender. Video Link: http://www.history.com/topics/world-war-ii/world-war-ii-history -
Canada's 100th Birthday
Canada celebrated its 100th birthday this year. Video Link: https://www.youtube.com/watch?v=18-oRTLIe3I -
First Man on the Moon
Neil Armstrong became the first man on the moon. The put a U.S. flag on the moon as well as a sign Video Link: https://www.youtube.com/watch?v=RMINSD7MmT4 -
J.K. Rowling Published Harry Potter and the Philosopher's Stone
Harry Potter and the Philosopher's Stone was published in the UK. The book is instantly a success and won several awards. -
Pope Francis became Pope
Pope Francis became the 266th pope. Video Link: http://www.cnn.com/videos/tv/2015/09/21/pope-francis-life-before-papacy-jorge-mario-bergoglio-org.cnn/video/playlists/pope-francis-visits-cuba-and-u-s-/
