Periodic Classification of Elements

So far Scientists have discovered 118 elements. Some of these elements are in free states, while the others in combined state. But all these elements were not discovered in a day. It has taken a long time to do so. When a very few elements were known, study of these elements were easier. But with the increase in the number of elements, it became difficult to study the properties of all of them separately. So an attempt has been made from time to time to classify these elements into groups, depending upon their physical and chemical properties. The study of the properties of element of a particular group helps the scientists to predict the properties of other elements of that group. In this chapter we will discuss about the classification of the elements into various groups on the basis of their properties.