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Ideasabout Atoms By Kürşat Keleşoğlu
Democritus • The theory of Democritus and Leucippus held everything to be composed of atoms, which are physically, but not geometrically, indivisible; that between atoms lies empty space; that atoms are indestructible; have always been, and always will be, in motion; that there are an infinite number of atoms, and kinds of atoms, which differ in shape, and size
Elements are made up of indivisible and undestructable so little particles. • Chemical reactions are results of seperating or combining atoms. • Atoms come together and form molecules. • Molecules of one compound are the same John Dalton
Experiments by J.J. Thomson in 1897 led to the discovery of a fundamental building block of matter. • In Thomson's model, electrons were free to rotate in rings which were further stabilized by interactions between the electrons, and spectra were to be accounted for by energy differences of different ring orbits. J. J. Thompson
The mathematical model of Brownian motion has several real-world applications. Brownian Motion Theory
Ernest Rutherford • Ernest Rutherford publishes his atomic theory describing the atom as having a central positive nucleus surrounded by negative orbiting electrons. This model suggested that most of the mass of the atom was contained in the small nucleus, and that the rest of the atom was mostly empty space but J. Thomson considered that the structure of an atom is something like a raisin bread, so that his atomic model is sometimes called the raisin bread model. He assumed that the basic body of an atom is a spherical object containing N electrons confined in homogeneous jellylike but relatively massive positive charge distribution whose total charge cancels that of the N electrons.
The Geiger–Marsden experiment (also called the Gold foil experiment or the Rutherfordexperiment) was an experiment to probe the structure of the atom performed by Hans Geiger and Ernest Marsden in 1909. The unexpected results of the experiment demonstrated for the first time the existence of the atomic nucleus, leading to the downfall of the plum pudding model of the atom, and the development of the Rutherford (or planetary) model. Alpha-particle scattering
In 1932 Chadwick heard of a new method of detecting particles emitted by radioactive elements developed by Irene Joliot-Curie, one of Marie Curie's daughters, and her husband, Frederic. He used this new technique and discovered that there were different particles in the nucleus which were neutrally charged.These particles became known as neutrons and revolutionised the study of radioactive elements. Soon after this, neutrons were used to bombard uranium atoms, which lead to the discovery of nuclear fission and the development of both the atomic bomb and nuclear power. • Because proton numbers of the atoms of the same element are the same so we need to have difference between atoms of the same elements. When we see neutron numbers are different in the atoms of the same element we see that isotopes exists. James Chadwick
Quarks • In physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and anti-quarks which give rise to the quantum numbers of the hadrons
