discovery of cosmic rays

Since atoms on the whole are neutral, the presence of negatively charged electrons suggested the presence of positively charged particle..

Production of cathode rays - In 1885, Sir William Crookes carried out a series of investigations into the behaviour of metals heated in a vacuum. The experiment of Crookes and others showed that a heated cathode produced a stream of radiation, which could cause gases at low pressure to gl..

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 that the ur..

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 opaqu..

Electron - Discharge Tube experiments - These experiments were conducted in detail by J.J. Thomson and he studied the passage of electricity through gases at extremely low pressure in a cylindrical glass tube. It was discovered that at extremely low pressure, gases become conductors of electricity ..

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 sulphate over photogra..

The discovery of cathode rays led to a vast field of practical application in Electronics. The glow produced by the fast moving electrons on a fluorescent screen led to its use in radar and television. The oscilloscope has many points in common with the discharge tube. In the o..

All radioactive decays follow first order kinetics. Therefore, the half-life of a radioactive element is independent of the amount of sample. With the help of half-life values of a suitable radioisotope of an element, which is present in a rock, or in an artefact, the age of the rock and the artefa..

Radiocarbon dating of historical wooden - derived objects is based on the knowledge that the cosmic ray intensity (responsible for 1 4 C production) has been practically constant for thousands of years. 1 4 C is formed in the upper atmosphere by the action of co..

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..