Periodic Table Properties

Introduction :

According to modern periodic law, the properties of the elements are the periodic functions of elements.

The properties of the elements which are dependent of the electronic configuration of elements are called the periodic properties.  These are called periodic because these are repeated as the element of similar electronic configuration is turn up.  The physical properties of the elements can be divided in to two categories:

properties in the Periodic table of which are characteristics of an individual atom are written with their general trends across a period and down the group respectively

Electro negativity: Increase across the period and decreases down the group.

Ionization Potential: Increases across the period and decreases down the group.

Electron Affinity: Increase across the period and decreases down the group.

Atomic Radius: decrease across a period and increases down a group

Ionic Radius: decrease across a period and increases down a group. 

Effective Nuclear Charge : Increase across the period and remains almost same in the subgroup of normal elements down the group.

Valency: Valency of the atom with respect to oxygen increases increase fromm1 to 7 across a period. Down a group it remains almost same

Screening Effect: Increase across the period and increases down the group. Electropositive or Metallic: character decrease across a period and increases down a group.
Electronegative or non metallic character: Increase across the period and decreases down the group.

Properties which are the characteristics of group of atoms are like:-     

• Melting point : the  melting point of  the element first increase and becomes somewhat maximum at the middle and then decreases ,  down the group the melting point there is regular change but it is different for different groups, for example in case of the Alkali metals the melting points decrease down the groups in case of Halogen it increases

• Boiling point: the  melting point of  the element first increase and becomes somewhat maximum at the middle and then decreases ,  down the group the melting point there is regular change but it is different for different groups, for example in case of Alkali metals the melting points decrease down the groups in case of Halogen it increases

Let us see some properties of periodic table.

Properties of Periodic Table

Similarly there is periodicity in the following properties of the groups of the atoms of the elements.
Heat of fusion, Heat of vaporization, Density,  Atomic volume, Nature of oxide .Nature of hydride. 
Since electronic configuration of the elements is the periodic table functions of atomic number of the elements therefore these atomic properties are also the periodic functions of atomic numbers of the elements and hence they are called the periodic properties. The general trends of some of the some periodic properties are as:-
Atomic and ionic radii  decrease in a period from left to right and increases in a group from top to bottom.
Electron gain enthalpy increases from left to right and decreases from top to bottom in a group.
Ionization potential increases from left to right in a period and decreases from top to bottom in a group.
Nature of oxide the acidic character of oxide increases from left to right in a period. 
Electro negativity increases from left to right in a periodic table and decreases from top to bottom in a group.