What are the defects of Mendeleev's periodic table?
Open in App
Solution
Mendeleev's periodic table:
According to Mendeleev's periodic table, the elements were arranged in an order of increasing atomic mass.
Demerits of Mendeleev's periodic table:
Certainly, no fixed position can be given to hydrogen in the Periodic table.
There are three elements in the fourth, fifth, and sixth periods, the reason for which was not given.
Isotopes were discovered long after Mendeléev had proposed his periodic classification of elements.
The periodic table cannot accommodate the presently known 118 elements.
"The atomic masses do not increase in a regular manner in going from one element to the next. So it was not possible to predict how many elements could be discovered between two elements — especially when we consider the heavier elements"
The elements present in Lanthanides and actinides that were discovered later, can not be placed in his periodic table.
The periodic table contains elements of dissimilar properties together and separates elements of the same properties. Such as barium and lead are, separated into second and fourth groups.