What were the main demerits of Mendeleev’s periodic table? (i) Hydrogen has been placed in group I though it resembles to group VII as well. (ii) Position of some elements was not justified. (iii) Isotopes were not given separate places. (iv) Lanthanides and actinides were not included in the table.

Question

What were the main demerits of Mendeleev’s periodic table? (i) Hydrogen has been placed in group I though it resembles to group VII as well. (ii) Position of some elements was not justified. (iii) Isotopes were not given separate places. (iv) Lanthanides and actinides were not included in the table. (A) (i), (ii) and (iii) (B) (i), (ii), (iii) and (iv) (C) (ii) and (iv) (D) (i), (iii) and (iv)

Tardigrade Admin · Accepted Answer

Correct answer is (b) (i), (ii), (iii) and (iv)