Periodic classification of Elements
Think of a morning prayer in your school. Students stand in rows which are horizontal as well as vertical. Each class stands in a single line, height wise. Generally, height of students of class I is the shortest and that of class 12 is the tallest.
The vendor in a medical store could locate the medicines we seek in a flash of time with the use of a pattern they are arranged. We can easily identify the books in the library as quickly as possible.
There is a pattern in all these cases and this pattern makes the selection easy. (Pattern: regular arrangement)
We live in the world of substances with great diversity. The substances are formed by the combination of various elements. All the elements are unique in their nature and property. To categorize these elements according to their properties, scientists started to look for a way. In 1800, there were only 31 known elements. By 1865, their number became 63. Now 118 elements have been discovered. As different elements were being discovered, scientists gathered more and more information about the properties of these elements. They found it difficult to organize all that was known about the elements. They started looking for some pattern in their properties, on the basis of which they could study such a large number of elements with ease. Let us discuss the concepts of classification of elements proposed by various scientists from early to modern period.