What is the usual number of valence electrons in the atoms of the last element in a period ?

What property do all the elements on the same group of the periodic table as fluorine have in common ?

What is the number of valance electrons in the atoms of first element in a period ?

State whether the following statement is true or False :

On going down in a group of the periodic table, the number of valence electrons increases.

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