Question

Which of the following is an limitation of Mendeléev’s periodic table?

• A. The noble gases could be accommodated in a different group of the periodic table without disturbing the existing order.
• B. He predicted the existence of some elements that had not been discovered at that time.
• C. The position of hydrogen could not be fixed in the periodic table.
• D. 62 elements were grouped based on similarity in their chemical properties.

Answer 1

The correct option is C The position of hydrogen could not be fixed in the periodic table.

Few limitations of Medeleev’s periodic table are as follows:

• The atomic masses did not increase in a regular manner in going from one element to the next.
• The position of hydrogen could not be fixed. Just like halogens it reacts with metals and non-metals to form covalent bonds. However, its electronic configuration is similar to that of alkali metals.
• Isotopes were discovered later. These posed another challenge Mendleev’s periodic law.