emitation of radiations and nature of rediations from radioactive substance

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..

Radioactivity - 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 matter. In 1896, Henri Becquerel discovere..

The phenomenon of spontaneous disintegration of an unstable nucleus of naturally occurring isotope accompanied by emission of active radiations line a , b and g radiations is known as Natural Radioactivity. These radiations come from..

It is a nuclear phenomenon. It is due to the instability of the nucleus. It is a spontaneous, continuous and irreversible process. It is independent of external factors such as pressure, temperature, state of substance, electrical field, magnetic field, catalyst etc. A ..

In astronomy, the low temperature microwave radiation that arrives at the earth's surface from all directions of outer space is called background radiation. It is so named because it forms a background to all the radio sources that have been detected by radio telescopes. Cosmic ..

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 uranium ..

When certain metals are heated to a high temperature, they emit thermions (electrons) and the phenomenon is called thermionic emission Cathode rays are a stream of negatively charged particles emitted from the cathode of an evacuated bulb, when a voltage of nearly 3000 volt..

Artificial Nuclear Reactions - Radioactivity is broadly classified into two categories: a) Natural radioactivity and b) Artificial or Induced radioactivity. If a substance emits radiations by itself, it is said to possess na..

The substances/species produced either by a natural source or by human activity, which cause an adverse effect on the environment on being in excess of a desirable limit, are termed as pollutants. Some common examples of pollutants are carbon monoxide, sulphur dioxide, oxides of..

In 1960, T .H. Maiman constructed the first laser using a Ruby crystal. Ruby is a crystalline form of silica(Al 2 O 3 ) with a slight natural doping of chromium. It has the following advantages for being used as a laser. (i) It is a solid having suitably arranged energy levels. (ii) It is..