On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.

State the merits of Mendeleev's periodic table.

Which is the first element in the periodic table ?

What is the position of Actinoids in the periodic table?

What are the demerits of Mendeleev's periodic table?

Which elements in the periodic table are transition elements?

The lanthanides are placed in the periodic table at

Which is the incomplete period in the Moders periodic table?

Write the answers of the question with refernce to the structure of the periodic table. Which elements are present near the zig zag line?

Name the following: The three metals in the third period of the modern periodic table.

Two elements X and Y have atomic number 12 and 16 respectively.Write the electronic configuration for these elements.To which period of the Modern periodic table do these two elements belong?