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Dalton atomic theorie.
Dalton drew upon the ancient Greek idea of atom (the word atom come from the Greek atomos meaning indivisible). His theory star that atoms are indivisible, those of a given element are identical, and compounds are combinations of diferent types of atoms. -
J.J Thomson.
Thomson discovered electrons in atoms in 1897, for whic he won the Nobel Prize. He subsequently produced the plum pudding model of the atom. It shows the atom as composed of electrons scattered throughout a spherical cloud of positive charge. -
Ernest Rutherford.
Rutherford fired positively charged alpha particles at a thin sheet of gold foil. Most passed through with little deflection, but some deflected at large angles. This was only posibly if the atom was mostly empty space, with the positive charge concentrated in the centre, this its called the nucleous. -
Niels Bohr.
Bohr modified Rutherford model of the atomby stating that electrons moved around the nucleaous in orbits of fixed sices and energies. Electron energy in this model was quantised, electrons could not occupy values of energy between the fixed energy levels. -
Erwin Schrödinger.
Schrodinger started at electrons do not move in set paths around the nucleus, but in waves. It its impossible to know the exact location of the electrons, instead we have clouds of probability called orbitals, in which we are more likely to find an electron.