j.j thomson's atomic theory

Models of Atom - J.J Thomson's and Rutherford's Models - After the discovery of electrons and protons it was necessary to know how these particles are arranged within the atom. Various scientists tried to describe this structure and after subsequent improveme..

After the discovery of electrons and protons it was necessary to know how these particles are arranged within the atom. Various scientists tried to describe this structure and after subsequent improvements through experiments, the structure of an atom is well defined today..

J.J.Thomson proposed the first simple and most primitive model in 1898, which considered an atom to be a sphere of uniform positive charge into which the negatively charged electrons were embedded. This model was like a plum pudding dotted with raisins and was thus called as 'p..

'. The electrons are like plums in a pudding (positive charge). The seeds in a watermelon fruit can be given as a parallel comparison. With this model he tried to explain the observed spectra of elements. According to him, the vibrations of electrons would give rise to electromagnetic energy radiat..

J. J Thomson the discoverer of the electron believed that the atom is a uniform sphere of positive charge with electrons (raisins) embedded in it. This model explained the electrical neutrality of atom, but it failed to explain how these fundamen..

. In 1793, he left for Manchester to teach physics and chemistry in a college. In 1801, he observed and discovered the law of expansion of gases on heating. He also enunciated the law of partial pressures and found methods of determining vapour pressure of gases. He invented the dew point hygromete..

Dalton's Atomic Theory Modern Atomic Theory All matter is made up of extremely small particles called atoms An element is made up of extremely small particles called atoms Atoms are indivisible and indestr..

John Dalton, a British school teacher, published his theory about atoms in the year 1808. His findings were based on experiments and also from laws of chemical combinatio..

John Dalton provided a simple theory of matter to provide theoretical justification to the laws of chemical combinations in 1805. The basic postulates of the theory are: All substances are made up of tiny, indivisible particles called atoms. Atoms of the same..

In view of new discoveries about atoms, Dalton's atomic theory was modified as given below: * Atom is no longer indivisible as it has a complex structure of sub atomic particles (electrons, protons and neutrons). * Atoms of..