Nuclear chemistry is a branch of chemistry which deals with the study of reaction involving nuclear changes. A study of this not only helps to understand the atomic structure but also leads to a pathway to use the radioactive tracers for a number of technological applications. Nuclear fission and fusion provide us with a vast source of energy there by reducing our dependence on fossils fuels. This surplus amount of energy produced can be used for destructive purposes also. Solar energy which is the root cause for the survival on the earth is derived from the nuclear fusion. Hence it is left to us to use it only for peaceful and useful purpose.
RADIACTIVITY- Henri Becquerel in 1896, while performing experiments with uranium compounds accidentally placed a crystal of potassium Uranyl Sulphate over a photographic plate wrapped with black paper. On developing the photographic plate he found a dark spot. Becquerel concluded that uranium emitted certain rays which penetrated the wrapped paper and affected the photographic plate. This phenomenon of spontaneous emission of radiation by an element or its compound is called radioactivity. The elements which emit such radiation are called radioactive elements.
Radioactivity can be can be classified in to natural and induced radioactivity. Natural radioactivity is a phenomenon in which a substance emits radiation itself. In induced radioactivity is a phenomenon in which a substance which does not possess radioactivity starts emitting radiation on exposure to rays from a natural radioactive substance.
NATURE OF RADIATIONS EMITTED FROM RADIOACTIVE SUBSTANCE- In 1904 Rutherford and his co-worker passed the radiations from radioactive elements through a strong electric field between parallel plates and separated them in to three different kinds of rays.
ALPHA RAYS- the rays which are deflected towards the negative plate are called alpha rays and show that they carry positive charge.
BETA RAYS- The rays which are deflected towards the positive plate are called beta rays and show that they can carry negative charge.
GAMMA RAYS- The rays which are not deflected at all show that they do not carry any charge and are known as gamma rays.