What property do all elements in the same column of the Periodic Table as fluorine have in common?

What would be the nature of oxides formed by the elements on the right-hand side of the periodic table?

Give two reasons to explain how the metallic character of elements varies: $(a)$ in a group,$(b)$ in a period.

On moving from left to right in a period in the periodic table,the size of the atom.

Three elements $A$, $B$, and $C$ have $3$, $4$, and $2$ electrons respectively in their outermost shell. Determine the group number to which they belong in the Modern Periodic Table and state their valencies.

$(a)$ Electropositive nature of the element$(s)$ increases down the group and decreases across the period.
$(b)$ Electronegativity of the element decreases down the group and increases across the period.
$(c)$ Atomic size increases down the group and decreases across a period (left to right).
$(d)$ Metallic character increases down the group and decreases across a period.
On the basis of the above trends of the Periodic Table,answer the following about the elements with atomic numbers $3$ to $9$:
$(a)$ Name the most electropositive element among them.
$(b)$ Name the most electronegative element.
$(c)$ Name the element with the smallest atomic size.
$(d)$ Name the element which is a metalloid.
$(e)$ Name the element which shows maximum valency.