preview

History Of Atom Research Paper

Good Essays
The history of the atom
The earliest recorded theory of the atom first came about when Greek philosopher Democritus, in 460AD thought about division of sand grains. He thought that substances could be broken down until they could no longer be made smaller, he called this particle the atomos and this is where the word atom comes from.
John Dolton, in the 19th century, was the next person to develop the idea of the atom. His studies on gases he created five assumptions about atoms, some of which are still relevant today: all matter is composed of atoms, atoms cannot be created or destroyed, all atoms of the same element at identical, chemical reactions occur when atoms are rearranged, compound are formed by the combination of two or more atoms.
…show more content…
the alpha particle. Ernest Rutherford tested the structure of an atom by bombarding a thin sheet of gold foil with alpha particles. Most of the alpha particles passed though the atom but some reflected or even bounced of the gold foil. Rutherford concluded that there was a positive group of particles in the centre of the atom he revised Dalton’s original model and said that atoms were made up of a positive nucleus of protons and that the electrons orbited this centre. He was unable to explain why the electrons orbited the nucleus and did not spiral inward as they lost…show more content…
two different directions to the spin. He also gave the world a rule to dictate how an electron in an atom would behave. Pauli’s exclusion principal states that, “if an electron has a certain set of quantum numbers then no other electron in that atom can have the same set of quantum numbers.”
When 1926 came Erwin Schrödinger another Austrian physicist built upon Einstein and Louis de Broglie’s idea of wave particle duality. He developed a mathematical Equation that related the pattern of electrons with that of waves, he gave his wave mechanics the symbol psi .
In 1932 James Chadwick discovered a second particle in the nucleus, he fired alpha particles at beryllium and found that neutrons were released. He revised Bohr’s model of the atom to include a representation of both protons and neutrons in the visual diagram.
Today we know that electrons orbit a nucleus made up of protons and neutrons and that the electrons can be described as both waves and
Get Access