Mendeleev Periodic Table: Merits and Demerits | Achievements

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When classifying elements in chemistry and fitting practical and theoretical applications, the periodic table, such as Mendeleev periodic table, plays an important role. Although the Genesis of the classification of elements also suggests the positions on the tables, the most prominent among them is the Mendeleev periodic table. If you are not sure about this table and want to know more about it, then give this blog a few minutes to understand what the periodic table is all about :

Mendeleev Periodic Table Class 10:

A periodic table is designed by arranging the elements in vertical column horizontal rows; Mendeleev periodic table is arranged in the increasing order of the atomic weight that the elements with similar properties occupy the equivalent vertical group or column. The elements in this periodic table are arranged in 7 horizontal rows, known as periods, and 8 vertical columns, known as groups. It is an evolved version of the periodic table, known as a remarkable achievement for laying the foundation for developing the modern periodic table. Mendeleev periodic table is based on the element’s Atomic Mass.

If you are curious about the different properties of the elements in this periodic table, then you can go through the elements that are present in Mendeleev’s periodic table here:

Mendeleev Periodic Table

Achievements of Mendeleev periodic table:

  • This periodic table consists of 8 groups with 9 elements arranged in triads.
  • The elements in this table are arranged into 7 horizontal rows known as periods; on the other hand, it has 8 vertical columns known as groups.
  • The eight groups in the table were labelled in Roman numbers and then divided into groups group A and B on the basis of their similarities.
  • Noble gases were present or placed in a different or separate group called the zero group. It was done so that it won’t disturb the main periodic table.
  • The periodic table had blanks or gaps left behind for new elements. These elements were added later after discovering them.

Merits and demerits of Mendeleev periodic table:

Every periodic table comes with some merits and demerites so does the Mendeleev periodic table. Let sus know about them here:

Merits of Mendeleev periodic table:

What are the merits of the Mendeleev periodic Table? If this is hovering around your mind, then here are some of the merits

  • The table is based on a systematical classification of elements’ data based on their properties. It was symmetrical in terms of categorizing the elements.
  • As Mendeleev left space for the elements predicted in the periodic table, after anticipation as per their properties after their discovery, these were placed in the gaps or blanks without much change.
  • After studying the position of elements in the periodic table, Mendeleev corrected the atomic masses of these elements, which is an important achievement and one of the advantages of Mendeleev periodic table.

Demerits of Mendeleev periodic table:

Are there any limitations of Mendeleev periodic table? Yes, there are. Let us know about these here:

  • One of the significant demerits was placing certain elements in the wrong group based solely on their atomic weights. For instance, iodine was placed in the same group as chlorine and fluorine, although it had more similarities with the elements in the group below.
  • Moreover, the Mendeleev periodic table could not explain the existence of isotopes and radioactive elements discovered later. It was one of the major drawbacks of Mendeleev’s periodic table.

Difference between Mendeleev and Modern Periodic Table:

The modern periodic table is an enhanced version of the Mendeleev periodic table. It was developed by scientists such as Henry Moseley and Glenn T. Seaborg, who discovered the concept of atomic number. The modern periodic table arranges the elements in order of increasing atomic number instead of atomic weight, which makes it more accurate and reliable. The modern periodic table also includes lanthanides and actinides, which were not included in the Mendeleev periodic table.

The difference between the Mendeleev and modern periodic tables lies in their arrangement of elements. Mendeleev arranged the elements based on their atomic weight and grouped them according to their chemical properties. On the other hand, the modern periodic table arranges the elements based on their atomic number and groups them based on their electron configurations. The modern periodic table also includes noble gases, which were not known during the time of Mendeleev.


To sum up, the Mendeleev periodic table was a significant advancement in chemistry, but it had limitations. We hope that with this blog, you can grasp the Merits and demerits of Mendeleev periodic table. Let us know in the comments if you want to know more about this topic.

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What is Mendeleev periodic table?

Mendeleev’s periodic table is named after the famous Russian chemist Dmitri Mendeleev. This periodic table was first published in 1869 and was widely accepted by the scientific community then. It was significant progress in chemistry as it organized the elements to make understanding their properties and behavior easier. Mendeleev arranged the elements in order of increasing atomic weight and grouped them based on their chemical properties.

How many periods are there in Mendeleev periodic table?

The table has sixty-three elements, and it consists of six Periods.

What are the limitations of Mendeleev periodic table?

Mendeleev’s periodic table had some demerits, which are as follows:

  • He was not able to locate hydrogen in his periodic table.
  • With the discovery of isotopes of elements and Mendeleeve’s periodic law was violated.
  • The number of elements was not predictable as there was an increase in atomic mass, and the mass was not regular while moving from one element to another.

How many groups and periods are in Mendeleev periodic table?

It has 6 Periods and 8 groups.

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