introduction about periodic classification of elements

Introduction - At the turn of the nineteenth century, about 30 elements were known. 50 years later by the 1850s, scientists had discovered sixty three chemical elements and the numbers kept increasing. With the discovery and study of more and more elements an..

Introduction - With the rapid development of Chemistry and the discovery of new elements, it was necessary to develop a simple way to study and remember the numerous properties of the elements and their compounds. This gave rise to the necessity of classificationh..

Introduction - In the famous atomic theory of John Dalton (1805), it was suggested that the atoms of an element have a characteristic mass. So, attempts were made to classify elements on the basis of their atomic masse..

Introduction - The long form of the periodic table is based upon the filling of a particular shell and has been accordingly divided into four blocks i.e. 's', 'p', 'd' and 'f' blocks. The 's' block elements involve the filling of 's' subshell. This block includes the h..

The recurrence of similar properties of the elements when they are arranged in the order of increasing atomic number, after certain regular intervals, is called periodicity..

Dobereiner's Triads - In the famous atomic theory of John Dalton (1805), it was suggested that the atoms of an element have a characteristic mass. So, attempts were made to classify elements on the basis of their atomic masses. In the year 1829, Johann Wolfgang Dobereiner, a Ger..

Oxygen, sulphur, selenium, tellurium and polonium constitute the group 16 of the periodic table of elements. The first four elements are collectively called CHALCOGENS. The name derives from the Greek word for bronze and points to the association of sulphur and i..

Introduction - The p-block contains several elements of great social and economic importance as well as chemical interest. Examples include the use of aluminium as a structural material, the importance of silicon and germanium as semiconductors, and the use of sulphur, phosphoru..

All elements in the periodic table have been classified as metals and non-metals. The non-metals are placed on the right hand side of the periodic tabl..

With the rapid development of Chemistry and the discovery of new elements, it was necessary to develop a simple way to study and remember the numerous properties of the elements and their compounds. This gave rise to the necessity of classification of the el..