Mention the number of group in which three elements of different physical state are present.

Which is different in different groups?

Give an example of a compound in which the same elements exists in two different oxidation states.

mention the number of periods and groups in the long form of the periodic table.

Which is different in different groups ?

Why do elements in the sae group show similar properties but the elements in different groups show different properties?

There are nine electrons in the 5f-orbital of an atom of an element. Mention the maximum number of electrons which have the same spin and number of unpaired electrons.

Write the group number of s,p and d-block elements in periodic table.

The compounds in which the elements of group- 14 show an oxidation state of +4 are expected to be covalent, whereas the compound in which they show an oxidation state of +2 are expected to be ionic-explain with reason.

Mention a group which strongly deactivates benzene ring .