Three elements $B, Si$ and $Ge$ are:

Two elements $X$ and $Y$ have atomic numbers $11$ and $16$ respectively.
$(a)$ Write the electronic configuration of both.
$(b)$ Which type of bond will they form?
$(c)$ Write the formula of the compound formed by their combination (in terms of $X$ and $Y$).

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

Three elements $X$,$Y$,and $Z$ having atomic numbers $11$,$7$,and $6$ respectively react with oxygen to form their oxides.
$(a)$ Arrange these oxides in increasing order of their basic nature.
$(b)$ Give reason for your answer.

Which one of the following depicts the correct representation of atomic radius $(r)$ of an atom?

$(a)$ What is the basis of arranging the elements in the Modern Periodic Table?
$(b)$ How does this remove the problem of positioning of isotopes?