Of the following pairs,the one containing an example of metalloid elements in the periodic table is:

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.

Which of the following is $Not$ predominantly acidic or amphoteric oxide?

Which of the following is the correct order of acidic strength for $Al_2O_3$,$SiO_2$,$P_2O_3$,and $SO_2$?

$Fe$ is placed in the eighth group of the periodic table. What is the number of electrons in its outermost orbit?

Which one is the strongest acid?