Where would you locate the element with electronic configuration $2, 8$ in the Modern Periodic Table?

$(a)$ State the main characteristics of elements on which the modern periodic table is based.
$(b)$ No fixed position can be assigned to hydrogen in the periodic table. Why?

An element is placed in $2^{nd}$ Group and $3^{rd}$ Period of the Periodic Table,burns in the presence of oxygen to form a basic oxide.
$(a)$ Identify the element.
$(b)$ Write the electronic configuration.
$(c)$ Write the balanced chemical equation when it burns in the presence of air.

The following table shows elements represented by the letters $A, B, C, D, E, F, G$ and $H$.

Group	$1$	$2$	$13$	$14$	$15$	$16$	$17$	$18$
Element	$A$	$B$	$C$	$D$	$E$	$F$	$G$	$H$

$(i)$ Which of the elements has the atomic size:
$(a)$ biggest and $(b)$ smallest?
$(ii)$ Which element has valency:
$(a)$ $3$ and $(b)$ zero?

The element $X$ has the following electron configuration $2, 8, 8, 2$. It means that it belongs to:

Given below are some elements of the modern periodic table. Atomic numbers of the elements are given in the parentheses: $A(4), B(9), C(14), D(19), E(20)$.
$(a)$ Select the element that has one electron in the outermost shell. Also,write the electronic configuration of this element.
$(b)$ Which two elements amongst these belong to the same group? Give reason for your answer.
$(c)$ Which two elements amongst these belong to the same period? Which one of the two has a bigger atomic radius?