HISTORY OF ATOMS

What is an atom? An atom, in the simplest model, consists of a nucleus and orbiting electrons. There are only about 100 different kinds of atoms in the entire universe. Everything we see is made up of these 100 atoms in an unlimited number of combinations. How these atoms are arranged and bonded together determines whether the atoms make up a cup of water, a piece of metal, or the fizz that comes out of your soda can!

History of the atom-introduction The history of the study of the atomic nature of matter illustrates the thinking process that goes on in the philosophers and scientists heads. The models they use do not provide an absolute understanding of the atom but only a way of abstracting so that they can make useful predictions about them. The epistemological methods that scientists use provide us with the best known way of arriving at useful science and factual knowledge. No other method has yet proven as successful.

In the beginning Actually the thought about electricity came before atoms. In about 600 B.C. Thales of Miletus discovered that a piece of amber, after rubbing it with fur, attracts bits of hair and feathers and other light objects. He suggested that this mysterious force came from the amber. Thales, however, did not connect this force with any atomic particle.

Democritus Not until around 460 B.C., did a Greek philosopher, Democritus, develop the idea of atoms. He asked this question: If you break a piece of matter in half, and then break it in half again, how many breaks will you have to make before you can break it no further? Democritus thought that it ended at some point, a smallest possible bit of matter. He called these basic matter particles, atoms. According to Democritus, an atom is an indestructible and “uncut table” sphere. Nothing exists except atoms and empty space; everything else is opinion- Democritus Democritus

John Dalton John Dalton in (1803), in England, formed the atomic theory, which states that all matter is composed of tiny, indestructible particles called atoms that are all alike and have the same atomic weight. He proposed the Billiard Ball Model of atom.

Neils Bohr Neils Bohr in (1913), in Denmark stated that the electrons moved around the nucleus in successively large orbits. He also presented the Bohr atomic model which stated that atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. He called his model the Planetary model where electrons are moving around an orbit.

J.J Thomson J.J Thomson in (1898), in England - discovered the electron and developed the plum-pudding model of the atom. It is also called raisin bread model, and its called such because the electrons are loosely embedded in the sphere.

Erwin Shroedinger Erwin Shroedinger in (1926), in Austria introduced the Shroedinger Equation, a wave equation that describes the form of the probability waves that govern the motion of small particles and how these waves are altered by external influences.

Ernest Rutherford Ernest Rutherford (1909), England - used the results of his gold-foil experiment to state that all the mass of an atom were in a small positively-charged ball at the center of the atom. He called his model the Nuclear Model of an atom.

Heisenberg In 1927 Heisenberg, described atoms by means of formula connected to the frequencies of spectral lines. Proposed Principle of Indeterminacy or the Uncertainty Principle because you can not know both the position and velocity of a particle like electrons.

James Chadwick Chadwick in (1931), in England discovered the neutrally-charged neutron.

My own concept This is my concept a bomb shaped as a heart. It is a center of matter, there is light because it gives energy. It is more likely that more than a century will pass before we know the structure of the chemical atoms as thoroughly as we do our solar system. -Johannes StarkJohannes Stark This is my concept a bomb shaped as a heart. It is a center of matter, there is light because it gives energy. It is more likely that more than a century will pass before we know the structure of the chemical atoms as thoroughly as we do our solar system. -Johannes StarkJohannes Stark

Bibliography y/chapter_8/pages/history_of_atom.html y/chapter_8/pages/history_of_atom.html Brownian_motion/History.html Brownian_motion/History.html

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