Characteristics of the Modern or Long Form Periodic Table:
The main characteristics of the modern or long-form periodic table are mentioned below:
1: Base of Formation:
The modern periodic table is formed on the basis of the distribution of electrons in the orbits of atoms of the elements i.e. electronic configuration.
2: Same Electronic Configuration:
The electronic configuration of the outer shell of an atom of all elements in a class (but differing electron number) is the same. Therefore similarity is also found in the properties of these elements.
3: Start and End of a Period:
Each period starts by filling the electrons in the new core and ends with filling the outermost shells. That is why the first element in each period except the first period is the base metal and the last element is the inert gas.
4: Separate location of Metal, Non-metal, and Sub-metal:
Metallic non-metallic and sub-metallic elements have been kept separately in this periodic table. The metallic element is placed on the left side of the transition element and the non-metallic element is placed on the right side of the transition element.
5: Different types of elements placed in a different location:
Reactive metals in groups 1 and 2 of the s block, transition elements from the groups 3 to 12 of the d block, metals from the groups 13 to 17 of the p block, the inner transition elements are placed in the sixth (Lanthanide atomic number 58-71) and the seventh (Actinide atomic number 90-103) periods of the group third. Due to lack of space, they are shown separately under the periodic table and Inert or Noble gases are placed in group 18 at the end of the periodic table.
6: Relation between no. of the period and main cells:
The number of each period in this periodic table is equal to the number of main cells used in that period.
7: Place of Isotopic and Isobaric elements:
In this periodic table, the isotopic elements table is placed equal and the isobaric elements are placed in different places.
8: Possibilities of prediction of gradual changes of chemical properties:
In this periodic table, similarities in the chemical properties of elements and other gradual changes are felt by themselves.
9: The elements of all A groups:
The elements of all A groups are called common or replicate or representative elements.
Drawbacks of the long-form or modern periodic table:
There are mainly 4 drawbacks are available in the long-form of the modern periodic table which is mentioned below:
1: The position of hydrogen in this periodic table is not clear.
2: In this, lanthanide and actinide elements are kept separately below the periodic table which does not seem suitable.
3: The helium element should be in group 2 according to the electronic configuration but is placed in group 18 (due to inactivity).
4: The elements of the eighth group are placed in three vertical columns in groups of three which is an exception of one type.
The usefulness of modern periodic table:
The utility of the Modern or Long-form Periodic Table can be understood as follows:
1: Useful in the study of the Properties of Elements:
When the properties of one element of a group are known, information about the properties of all the elements of that group is obtained as there is a gradual change in the properties of the elements of each group.
2: Useful in the discovery of new elements :
Mendeleev left some spaces in his periodic table, later these elements were discovered in the modern periodic table and the spaces could be filled.
3: Useful in the separation of metallic and non-metallic elements:
The separation of metallic and non-metallic elements in the modern periodic table made their study and comparison of properties easier.