What happens to the metallic character of the elements as we go down in a group of the periodic table ?

What is the major characteristic of the first elements in the periods of the periodic table ? What is the general name of such elements ?

How do the atomic radii of elements change as we go from left to right in a period of the periodic table ?

How does the number of valence electrons vary on moving from left to right :

(i) in the first period of the periodic table ?

(ii) in the second period of the periodic table

How does the valency of elements change on moving from left to right in the third period of the periodic table ?