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Democritus named the building blocks of matter atomos, which means indivisible. He believed that atoms were uniform, solid, hard, incompressible, indestructible, and moved in infinite numbers through empty space until stopped. He theorised that atoms existed not only for matter, but also for such qualities as perception and the human soul. -
The Peloponnesian War was a 27 year long war in Greece between the Athenian Empire and the Peloponnesian League, headed by Sparta. It’s result was a victory for Sparta and a decline in the economy of Athens. -
Provided the first scientific atomic theory based on actual scientific experimentation, proving that Matter is made of solid “marble-like” particles. The mass of an atom decides the properties of that atom. -
Napoleon wanted to compel the Russian Empire into complying with the continental blockade of the United Kingdom. It is recognized as among one of history’s most devastating military endeavors. -
Faraday demonstrated through his laws of Electrolysis that an electric current can separate chemical compounds into their constituent elements. This supports the theory that electricity is responsible for the bond between atoms because by passing an electric current through a dissolved compound, one element would accumulate on one electrode while another element would accumulate on the opposite electrode, demonstrating that electrical forces are responsible for the bonds between atoms. -
Faraday demonstrated through his laws of Electrolysis that an electric current can separate chemical compounds into their constituent elements. This supports the theory that electricity is responsible for the bond between atoms because by passing an electric current through a dissolved compound, one element would accumulate on one electrode while another element would accumulate on the opposite electrode, demonstrating that electrical forces are responsible for the bonds between atoms. -
His study of cathode rays led to the discovery of the electron. He discovered that the cathode rays are made of electrons, which he calculated to be smaller than atoms. -
War fought between Spain and the United States of America. It was caused by Cuba’s struggle to gain independence from Spain, with the first attack happening in April of 1898 and ending in December of that same year. Its result was the United States gaining control over Spanish colonies. -
In May of 1911, Ernest Rutherford published his discovery of the atomic nucleus. He conducted an experiment in which he aimed a stream of alpha particles at a thin sheet of gold foil. A handful of the particles bounced off the sheet in such a way that suggested a collision with a small, dense atomic core. This experiment supported a model of the atom that indicated that most of the atom’s mass was concentrated in a nucleus. -
Neils Bohr published his model of the atom in 1913. It displays electrons orbiting the Nucleus at specific and discrete energy levels. These electrons only released or stole radiation when they jumped between their stationary energy levels. It is compared to the solar system because the electrons orbit the nucleus much like how the planets in the solar system orbit the sun. -
On June 28th, 1914, Archduke Franz Ferdinand of Austria was assassinated by Bosnian Serb student Gavrilo Princip, sparking the first world war. The Archduke was the heir to the throne of Austria, and Austria-Hungary immediately blamed the Serbia Government for the attack. This caused Austria-Hungary, alongside Germany, to declare war on Serbia on July 28, 1914. -
In 1916, Robert Millikan experimentally verified Einstein’s equation on the photoelectric effect. He proved that the value of Planck’s constant was the same as the value of h in Einstein’s equation. Up until Millikan’s experimentation, Einstein's hypothesis about photons had been considered controversial, and because of Millikan, it became non-controversial. -
Ernest Rutherford theorized the existence of the neutron in 1920. His colleague, James Chadwick, did an experiment that proved the existence of the neutron. He observed that when alpha particles collided with beryllium, they produced a new radiation. By measuring the energy of the radiation, he demonstrated that it consisted of neutral particles with masses similar to protons. -
Schroedinger was an Austrian physicist who used the wave-particle duality of the electron to create an equation that accurately described the behavior of an electron in the hydrogen atom. The Quantum Mechanical model of the atom comes from the solution to Schrödinger’s equation. -
In 1929, the stock market in the United States crashed, triggering the great depression. On the twenty-ninth of October, the market collapsed because of panicked selling, leading to huge losses for investors. Billions of dollars in stock were wiped out, and thousands of investors were ruined. -
Werner Heisenberg was a German physicist who worked on the theory of the atomic nucleus. He developed a model of proton and neutron interaction in an early description of the strong force. -
He discovered the neutron by doing beryllium bombardment experiments and interpreting that radiation is made of particles that are similar to protons in mass but have no electrical charge. These particles are neutrons. -
The Spanish Civil War was a military revolt against the Republican government of Spain. The rebels, often referred to as the Nationalists, received help from Nazi Germany and Fascist Italy. The Republicans received aid from the Soviet Union, along with the International Brigades. The International Brigades were made up of volunteers from Europe and the United States. In the end, however, the Nationalists took Spain, led by General Francisco Franco.