The periodic table is a table used in chemistry that is arranged according to the atomic numbers of the elements and it maintains the periodic law. In the periodic table, there are 118 elements and they are arranged in a way that maintains the periodic law. Till 2016 there were 114 elements. On 08 June 2016, the IUPAC approved more 4 elements with atomic number 113,115,117 and 118. Now, I will define the periodic table to you. I will also show which laws are maintained in the periodic table.

Introduction:

1. Every row is expanded from 1 to 18 groups.

2. Though the lanthanide and actinide series are given below, they are members of respectively 6th and 7th row.

3. There are two elements in the 1st row. There are eight elements, each of the 2nd and 3rd rows. There are 18 elements, each of the 4th and 5th rows. There are 32 elements in each of the 6th and 7th rows.

4. There are seven elements in the 1st and 18th group. There are six elements in the 2nd group and from 13th to the 17th group. There are 32 elements in group 3. There are four elements in each group 4 to 12.

The special names of elements present in various groups:

1. Alkali Metals: 

2. Alkaline Earth Metals:

There are 6 elements in group 2. These are beryllium, magnesium, calcium, strontium, barium and radium. We get these as compounds in the earth. And these create alkalies. And so we call this alkaline each metal.

4. Coin Metals:

In the group 11 of the periodic table, there are 4 elements. Among the except roentgenium other elements we're used in exchanging money in the past. So we call these coin metals.

4. Halogen Group:

Group 17 in the periodic table has 6 elements and these are fluorine, chlorine, bromine, iodine, astatine and tennessine. These elements are used in making salts. And so we call this halogen (halogen means-salt maker). We sometimes write it 'X'.

5. Inert Gases:

The 18th group of the periodic table consists of 7 elements. These are inert gases. These hardly do any reaction with other elements. And so we call these inert gases. These are helium, neon, argon, krypton, xenon and oganesson.

Some exceptions in the periodic table:

1. The place of hydrogen:

Hydrogen is a gas but it is placed with electropositive elements. Because hydrogen can release an electron like the alkali metals. On the other hand, it is a gas and it can take an electron like the halogens. But most of the characteristics of hydrogen is related to the alkali metals and so it is placed in the 1st group.

2. Lanthanide and Actinide series:

If we place the lanthanide and activist series in their place the beauty of the periodic table not remains. And so they are placed below the table.