discovery of radioactivity

The discovery of the phenomenon of radioactivity was purely accidental. In 1896, Henry Becquerel, a French scientist accidentally found that in presence of salt of uranium, photographic plates got heavily fogged even though they were wrapped in opaque paper. He concluded t..

Discovery of Radioactivity and Nature of Radiations - In 1896, the phenomenon of radioactivity was accidentally discovered by French scientist Henri Becquerel. He was performing experiments with uranium compounds. He accidentally placed a crystal of potassium uranyl su..

In 1896, the phenomenon of radioactivity was accidentally discovered by French scientist Henri Becquerel. He was performing experiments with uranium compounds. He accidentally placed a crystal of potassium uranyl sulphate over photographic plate wrapped with usual black pape..

The discovery of the electron towards the end of the nineteenth century was the starting point of new avenues of research in science, which were to give physicists an insight into the structure and nature of the atoms of matte..

Ernest Rutherford, an energetic New Zealander working in England, was studying the properties of particles spontaneously emitted by radioactive substances. Of particular interest was a positively charged, relatively heavy emission named alpha particle. Quantities of such particles are em..

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 'plum pudding' model o..

After the discovery of the radioactive particles, Rutherford performed an experiment where he bombarded a thin sheet of gold with a particles obtained from a radioactive substance. On striking the gold foil some of the a particles scattered and produced flashes on..

Summary - Atoms are made up of three fundamental particles: electrons, protons and neutrons. Discharge tube experiments by William Crookes and J.J. Thomson led to the discovery of electron. Goldstein's experiment with the discharge tube having a perforated cathode led to the discover..

'. 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..

Summary - Dalton had postulated that matter is made up of atoms, which are indivisible. Thomson was the first to suggest a structure for an atom. According to him, an atom is a positively charged sphere of radius=10 - 1 0 m in which the mass and the positive charge of the atom are uniformly distrib..