Atomic Model's (Sierra Miller)

Democritus

Jun 6, 1000

Actually born in 460 B.C , Democritus added that all matter consisted of extremely small particles that could not be divided. He figured this out by discourse. Discourse is when they would talk their way through it. This is actually how the earliest people made up their theory because they didn't have enough technology to be more specific.

Aristotle

Jun 6, 1001

Born is 384 B.C , Aristotle did not think there was a limit to the number of times matter could be divided. Both him and Democritus used discourse to figure out their theories of the atom. Once again, discourse is basically when you talk your way through it because the technology to be more accurate, wasn't available.

John Dalton

Jun 6, 1803

John Dalton's theory of the atomic model was that all matter is made up of individual particles called atoms which cannot be divided. Dalton said that atoms are tiny, industructible particles, with no internal structure. John Dalton did a lot of scientific experiments to support this theory and took an interest in predicting the weather; he correctly condluded that gas consists of individual particles. He measured the masses of elements that would combine when a compound forms for evidence.

Joseph John Thomson

Jun 6, 1897

J.J Thomson discovered the electron. Thomson's experiment, "plum pudding" model, contained a sealed tube of gas. There was a metal disk at each end of the glass, and almost airless, tube. Wires connect electricity to the metal disks. When the current is turned on, one of the disks was positively charged and the opposite one was negatively charged, with a glowing beam in the center. Think of chocolate chip ice cream, where the chips are negative and the vanilla cream is positively charged matter.

Hantaro Nagaoka

Jun 6, 1904

Hantaro was a Japanese physicist, who concluded that the atom has a nucleus in the center with electrons in orbit around it. He worked in the magnetostriction and was fascinated with Ludwig Boltzmann's course in kinetic theory of gases and Maxwell's work on the stability of Saturn's rings. He mainly studied earlier scientists theories and worked with them.

Ernest Marsden

Jun 6, 1909

Ernest Marsden assisted Rutherford in his Gold Foil experiment. Together they found out that the experiment didn't prove everything in Rutherford's first model so he came up with a new one. Marsden, in conducting this experiment, then proved Rutherford's new model correct. With Rutherford's original idea and Marsden's experiment together they proved that an atom has a dense, positively charged nucleus.

Ernest Rutherford

Jun 6, 1911

Rutherford's discovery of the atomic atom was that nucleus was dense and positively charged while electrons move in random spaces around it. He said that all the positive charge is concentrated in the central nucleus. Rutherford used the Gold Foil experiment to model this. He used a beam of alpha particles and aimed it at the gold foil in the middle of a screen, which flashes when struck by fast moving alpha particles. So he could figure out the path of the particles when the screen flashed.

Max Planck

Jun 6, 1911

Planck showed that atoms can absorb and emit light through scattering. He concluded this through working with light and other past theories.

Niels Bohr

Oct 30, 1913

Bohr discovered that electrons move in sphereical orbits at fixed distances from the nucleus. When an atom gains or loses energy, it can move from one energy level to another. Bohr's model is a quantum-physics based motification of Rutherford's model. Some sources combine the two and call it Rutherford-Bohr.

Louis de Broglie

Jun 6, 1924

Broglie proposes that electrons have properties of waves.His finding helped later scientists understand that the atom didn't behave like the solar system because electrons do not move in regular orbit.He used Einstein's relationship of wavelength lambda to momentum p, to purpose that this relationship would determine the wavelength of any matter.A group of physicists took an experiment where they fired electrons at a crystalline nickel target.The resulting diffraction pattern proved Louis right.

Werner Heisenberg

Jun 6, 1925

Werner's theory was called matrix mechanics which explained the behavior of atoms. Heisenberg based his theory on mathematical quantities called matrices. He concluded that charged particles bounce photons of light back and forth between them. Although him and Shrodinger weren't fond of each other, their work seemed to be quite similar in the mathematical part. They more than likely worked off what each other had said.

Erwin Shrodinger

Jun 6, 1926

Erwin Shrödinger was the first one to create mathematical equations to describe the motions of electrons in atoms. "Shrödinger's cat" was his experiment, although it was a thought experiment, otherwise known as a paradox. This experiment said that a cat would be alive and dead at the same time.

James Chadwick

Jun 6, 1932

James Chadwick was the person who confirmed the existence of neutrons, which have no charge.The existence of neutrons explained why atoms are heavier than the total mass of their protons and electrons. When the beryllium radiation hit hydrogen atoms in the wax, the atoms were sent into a detecting chamber. The collision with beryllium atoms would release massive neutral particles, what Chadwick called, neutrons.