The anomalies of Mendeleev's periodic table are:

1. The position of hydrogen were not clear in the Mendeleev's periodic table as the hydrogen shows the properties of both of group- IA and group VII A.
2. There were no proper places of isotopes of the same elements as the elements were arranged on the basis of atomic weight.
3. Mendeleev's periodic table did not have proper place for Lanthanides and Actinides.
4. Certain elements which appear to be chemically similar like Cu and Hg, Au and Pt, etc. had been placed in separate groups.
5. Certain elements which appear to be chemically dissimilar had been grouped together. For example, Cu, Ag and Au had been grouped together with Li, Na, K, etc.