Periodic classification of elements notes-Periodic Table

Was it easy to study the elements 150 years ago, as we do today? This was possible due to periodic classification of elements. Do you know what is the periodic table and periodic classification of elements and who did it when.

About 118 elements have been discovered so far and some new elements are still being researched. The properties and nature of all these elements are different. It is difficult to study them separately.

Periodic classification of elements
Periodic classification of elements

Realizing this difficulty, scientists of the time created a table to study them by classifying elements in a simple and easy way, called a periodic table. Elements in the periodic table are classified on the basis of similar properties.

Periodic classification of elements

Elements are classified into 7 different periods and groups based on their properties, called periodic classification of elements. Mendeleev's classification has seven periods and eight groups, while the modern periodic table has seven periods and nine groups. Elements are divided into different groups such as metals, non-metals, semi-metals and are also divided into alkali metals, alkaline earth metals, halogen and noble gases etc.

This article is so helpful for those who searching for “Periodic classification of elements class 10 notes”. And also so helpful for the student of class 11. We will learn more about Periodic classification of elements in different segments. Let us first discuss about Mendeleev's periodic table.

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Classification of elements in Mendeleev Periodic Table

The first systematic table on the classification of Element was introduced by Dmitry Mendeleev in 1869. It is based on the atomic weight of the element, which is called Mendeleev periodic table.

Mendeleev designed the table on the fact that new elements with similar properties would appear at certain intervals under the atomic weight of the elements.

In their periodic table, the horizontal wave has elements with similar properties called periods and the vertical columns are called groups.

These is the Mendeleev’s periodic table with names.

Mendeleev periodic table
Mendeleev periodic table

Mendeleev's periodic law

Mendeleev also formulated the periodic law to make the table. This law is called Mendeleev's periodic law. According to Mendeleev’s periodic law.

“The physical and chemical properties of elements are due to the periodic function of their atomic weight.”

Significance of Mendeleev's Periodic Table

  1. First of all, it has become easier to study chemistry by classifying the elements into different groups based on their properties.
  2. Inclusion in the periodic table for elements that can be detected in the future also helps in future study and research.
  3. Easy to adjust the atomic load of gold, platinum, uranium etc.

Errors in Mendeleev's periodic schedule

  1. Hydrogen was placed in group 1 with the alkali metal but the location could not be ascertained as it is a metal.
  2. Active alkali metals like LI, Na, K and less active metals like Cu, Ag, and Au are grouped together.
  3. Some elements did not follow Mendeleev's periodic law. That is, some elements with more weight are placed in top and some elements with less weight are placed bottom.

Classification of elements in Modern periodic table

  1. To address the shortcomings of Mendeleev's periodic table, chemists created a new periodic table called the modern periodic table.
  2. This periodic table is based on modern periodic rules. So the elements in this table are placed in ascending order of atomic numbers.
  3. In this table also the elements with the same properties are placed in the same vertical castle. This is called a group. Similarly, the elements are arranged in a horizontal wave based on the difference which is called period.

Modern Periodic table of elements list image file download.

Modern periodic rules

In 1913, scientist Henry Moses discovered that the properties of elements depended on atomic numbers, not on atomic weights. He formulated the modern periodic law in this concept, which is called modern periodic law. According to modern periodic rules.

“The physical and chemical properties of elements are due to the periodic function of their atomic numbers.”

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Features of the modern periodic table

   1. The modern periodic table has 7 periods, the format of which is as follows.

Period

First

2nd

3rd

4th

5th

6th

7th

No. of element

2

8

8

18

18

32

26

   2. The modern periodic table consists of 9 groups, including ‘VII’ and ‘0’ groups. It is         named in the following two ways.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

IA

IIA

IIIB

IVB

VB

VIB

VIIB

VIII

VIII

VIII

IB

IIB

IIIA

IVA

VA

VIA

VIIA

0

    3. Lanthanides and actinides are given separate places below the periodic table.

    4.Inert gases with zero valency are placed in the last group of the table, which is called         group 0.

    5. From Group IIIB to IIB, 10 elements are placed between the active metal and the               non-metal. These are called transition metals.

Difference between Mendeleev's and modern periodic table

S.N.

Mendeleev's Periodic Table

S.N.

Modern Periodic Table

 

1.

 

It is based on Mendeleev's periodic law.

1.

It is based on modern periodic rules. The groups also divided in to sub-groups.

2.

It has seven periods and eight groups

2.

It has seven periods and nine groups.

3.

The location of the isotope was unclear.

3.

It follows the principle that there is no need for a separate space for isotopes.

 

4.

The location of lanthanides and actinides was not clear.

4.

The location of lanthanides and actinides was also highlighted and placed below the table.

Definition of Some Important terms:

Lanthanides: A group of 14 elements from the element lanthanum with atomic number 57 to the lutetium with atomic number 71 is called lanthanides.

Actinides: A group of 14 elements from the element Actinium with atomic number 89 to the atomic number 103 to the atomic number lawrencium is called actinides.

Group ‘0’: The group of inert gases with zero valency is called group '0'.

Transition Metals: The 10 elements placed between the active metals and the non-metals from group ‘IIIB’ to ‘IIB’ are called transition metals.

Metals: Elements with full electrical conductivity are called metals. The metals are on the left in the periodic table. For example, Fe (Iron), Co (Cobalt), Ni (Nickel), Ag (Silver) etc.

Non-metals: Elements that do not have electrical conductivity are called non-metals. The non-metals are on the right in the periodic table. For example, F (Fluorine), Cl (Chlorine), I(Iodine) etc.

Semi-metals: Elements that have a partial electrical conductivity are called semi-metals. In the periodic table, semi-metals are placed between metals and non-metals. For example, Si (Silicone), Ge (Germanium), Bi (Bismuth) etc.

Conclusion: Due to the periodic classification of elements, today we are studying chemistry with great ease. Due to this, it is easy to do new research on the element.

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