Question

Which of the following is not a limitation of Mendeléev’s periodic table?

• A. Elements of lesser atomic weight were placed before the elements of higher atomic weight
• B. Position of isotopes was not fixed in the periodic table
• C. Position of hydrogen is not fixed
• D. Placement of similar elements at different positions and dissimilar elements at same positions

Answer 1

The correct option is A Elements of lesser atomic weight were placed before the elements of higher atomic weight

Mendeléev arranged elements in the order of their increasing atomic masses. So, elements of lesser atomic weight were placed before the elements of higher atomic weight. Therefore, this is not a limitation of Mendeléev’s periodic table.
Hence, the correct answer is option (a).