Q.52:- Discuss the main features of long form of the periodic table. What are the advantages of long . form of periodic table?
Main features of long form of periodic table:
- Groups. The vertical columns in the periodic table are known as groups. There are 18 groups in the long form of periodic table.
Each group having the same electronic configuration in the outermost shell.
- Periods. There are 7 periods in the long form of periodic table.
It is denoted by n which means highest principal quantum number.
- Lanthanoids. Group of 14 elements in the sixth period. They are placed after Lanthanum.
- Actinides. Group of 14 elements in the seventh period after actinium. Both Lanthanoids and actinoids are placed in separate panel at the bottom of the periodic table.
Advantages of long form of periodic table:
- It gives a suitable link between the position of element and its electronic configuration.
- On the basis of atomic numbers it easier to remember all the elements.
- The elements in the same group have similar properties due to their outer-most (valence shell) configuration. Thus it gives is a logical classification.
- Justified positions are provided to transition and inner transition elements. ‘
- It makes the study of elements systematic and simple.