FIRST hypotheses about the structure of matter
N ( % )
O ( % )
The ratio between the mass of oxygen that is combined with the same weight of nitrogen
(Carbon monoxide, dinitrogen / nitrous oxide)
(Dinitrogen trioxide / nitrogen dioxide)
0,57/ 1,71 = 1/3
(Dinitrogen pentoxide / nitrogen dioxide)
0,57/ 2,85 = 1 /5
(Carbon monoxide, nitrogen oxide / nitrogen)
0,57/ 1,14 = 1/2
(Dinitrogen tetroxide, nitrogen dioxide dimer)
0,57 / 2,28 =1/ 4
Also at the beginning of the century - nineteenth - century Avogadro made another fundamental law of chemistry that bears his name and which states the following: "Equal volumes in different agze, under the same conditions of temperature and pressure, have the same number of molecules. "
Although there crystallized the concept of "molecule", as a system made up of many atoms.
All these ideas have established the correct understanding of the structure of matter, in the sense that it is not continuous, but is composed of structural entities (atoms, molecules) to be studied in a new light, given that the correct understanding of the properties of any substance is subject to a clear understanding of its structure.
Identification of constituents atoms
During the entire nineteenth century, atoms continued to be considered elementary particles, indivisible, nepunandu the problem of investigating their possible internal structure.
Only at the end of the century (1897), J.J. Thomsom managed to emphasize electron constituent of the atom, as a negatively charged particle. The value of the electric charge of the electron was known, moreover, "the elementary electric charge" (it was determined for the first time indirect electrolysis experiments): e = e = 1,6 * 10-19 C.
In other words, the electric charge of the electron is:
Direct information on the electron experiments were obtained by passing electric current through a rarefied gas, given that they, under normal circumstances, have a low electrical conductivity. If you apply a voltage between two electrodes large enough at the ends of a tube containing dilute gas, arises an electric discharges (accompanied by luminous phenomena).
At low pressures (below 10-2 torr) luminous phenomena disappear inside the tube: instead the opposite wall of the cathode luminescence occurs due to radiation from the surface of leaves, called cathode radiation.
J.J.Thompson showed, by diverting these radiation with various external fields, as recorded deviations are independent of the nature of the gas found in the tube, and the nature of the material they are made of electrodes, which led to the conclusion that the particles consist of universal identical negative, so the electrons.
All J.J. Thompson managed to perform and interpret an interesting experiment deviated cathode radiation (using an electric field and a magnetic field parallel to each other), which was calculated based on the specific task of cathode radiation, so the electron specific task (relationship between electric charge and its mass:
(Q / m) rad.catodica = (que / me) = - 1.76 * 108 C / g
Noted with an electron mass me, which is therefore the value: