Which of the following sets of elements is written in the order of their increasing metallic character?

Which of the following sets of elements is written in the order of their increasing metallic character?

An element belongs to the third period and second group of the periodic table:
$(a)$ State the number of valence electrons in it.
$(b)$ Is it a metal or a non-metal?
$(c)$ Name the element.
$(d)$ Write the formula of its oxide.

An element is placed in $2^{nd}$ Group and $3^{rd}$ Period of the Periodic Table. It burns in the presence of oxygen to form a basic oxide.
$(a)$ Write a balanced chemical equation when this oxide is dissolved in water.
$(b)$ Draw the electron dot structure for the formation of this oxide.

The elements $Be$,$Mg$,and $Ca$,each having two electrons in their outermost shells,are in periods $2$,$3$,and $4$ respectively of the modern periodic table. Answer the following questions,giving justification in each case:
$(i)$ Write the group to which these elements belong.
$(ii)$ Name the least reactive element.
$(iii)$ Name the element having the largest atomic radius.

$(i)$ The elements of the second period along with their atomic numbers in parentheses are given below: $B(5)$,$Be(4)$,$O(8)$,$N(7)$,$Li(3)$,$C(6)$,$F(9)$.
$(a)$ Arrange them in the same order as they appear in the periodic table.
$(b)$ Which element has the largest and smallest atom?
$(ii)$ Why does the atomic radius change as we move from left to right in a period?