Two elements $P$ and $Q$ belong to the same period of the modern periodic table and are in Group $1$ and Group $2$ respectively. Compare their following characteristics in tabular form:
$(a)$ The number of electrons in their atoms
$(b)$ The sizes of their atoms
$(c)$ Their metallic characters
$(d)$ Their tendencies to lose electrons
$(e)$ The formula of their oxides
$(f)$ The formula of their chlorides

(N/A)

Property	Element $P$ (Group $1$)	Element $Q$ (Group $2$)
$(a)$ No. of electrons in the atom	$1$ more than the previous noble gas	$2$ more than the previous noble gas
$(b)$ Size of the atom	Larger	Smaller
$(c)$ Metallic character	More metallic	Less metallic
$(d)$ Tendency to lose electrons	Higher	Lower
$(e)$ Formula of oxides	$P_2O$	$QO$
$(f)$ Formula of chlorides	$PCl$	$QCl_2$

Explanation:
$1$. As we move from left to right in a period,the atomic size decreases due to an increase in effective nuclear charge.
$2$. Metallic character decreases from left to right because the tendency to lose electrons decreases.
$3$. Group $1$ elements have a valency of $1$,forming oxides $P_2O$ and chlorides $PCl$. Group $2$ elements have a valency of $2$,forming oxides $QO$ and chlorides $QCl_2$.