Which one of the following is/are correct statement(s) with respect to Mendeleev's periodic table?
Which one of the following is/are correct statement(s) with respect to Mendeleev's periodic table?
The correct options are
A The increasing order of atomic mass was not strictly followed.
C Elements with similar properties were placed in the same group.
D Elements are arranged according to their atomic mass.
Let us go through each one.
Elements are arranged according to their atomic mass.
In Mendeleev's periodic table he arranged the elements according to their atomic masses as he found that the physical and chemical properties of elements repeated at regular intervals. Based on this he proposed the Mendeleev's Periodic Law.
Elements with similar properties were placed in the same group.
Elements for the first time comprehensively classified in such a way that elements of similar properties were placed in the same group.
All the columns were filled with elements.
This statement is incorrect. Columns were left vacant for elements which were not known at that time.
The increasing order of atomic mass was not strictly followed.
The increasing order of the atomic mass was not strictly followed throughout. For example, cobalt and nickel were placed together. An element with higher atomic mass was placed before the lower atomic mass element. It was done in order to maintain the similarity in the chemical properties of elements belonging to the same group.
A
The increasing order of atomic mass was not strictly followed.
C
Elements with similar properties were placed in the same group.
D
Elements are arranged according to their atomic mass.
Let us go through each one.
Elements are arranged according to their atomic mass.
In Mendeleev's periodic table he arranged the elements according to their atomic masses as he found that the physical and chemical properties of elements repeated at regular intervals. Based on this he proposed the Mendeleev's Periodic Law.
Elements with similar properties were placed in the same group.
Elements for the first time comprehensively classified in such a way that elements of similar properties were placed in the same group.
All the columns were filled with elements.
This statement is incorrect. Columns were left vacant for elements which were not known at that time.
The increasing order of atomic mass was not strictly followed.
The increasing order of the atomic mass was not strictly followed throughout. For example, cobalt and nickel were placed together. An element with higher atomic mass was placed before the lower atomic mass element. It was done in order to maintain the similarity in the chemical properties of elements belonging to the same group.
