Identify the set of acidic oxides.

Consider the following four elements,which are represented according to the long form of the periodic table. Here $W$,$Y$,and $Z$ are left,up,and right elements with respect to the element $X$,and $X$ belongs to the $16^{th}$ group and $3^{rd}$ period. Then,according to the given information,the incorrect statement regarding the given elements is:

Which pair of elements has the same chemical properties?

Which of the following has the highest electropositive character?

Among the statements $(I-IV)$,the correct ones are:
$(I)$ $Be$ has smaller atomic radius compared to $Mg$.
$(II)$ $Be$ has higher ionization enthalpy than $Al$.
$(III)$ Charge/radius ratio of $Be$ is greater than that of $Al$.
$(IV)$ Both $Be$ and $Al$ form mainly covalent compounds.

The correct order of relative basic character of $NaOH$,$Mg(OH)_2$ and $Al(OH)_3$ is