Which of the following thermal stability orders is correct?

In which of the following are the $s$-block elements arranged in the correct order of their melting points?

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(I)$ Number of $S-S$ bonds in $H_{2}S_{n}O_{6}$ is $(n - 1)$.
$(II)$ When $F_{2}$ reacts with water,it gives $HF, O_{2}$ and $O_{3}$.
$(III)$ $LiNO_{3}$ and $BaCl_{2}$ compounds are used in fireworks.
$(IV)$ $Be$ and $Mg$ hydrides are ionic and polymeric.

Which of the following electronic configurations belongs to $s-$block elements?

Which of the following compounds gives oxygen on fast heating?
$I$. $AgNO_3$
$II$. $CaCO_3$
$III$. $Pb(NO_3)_2$
$IV$. $Na_2CO_3$

Which of the following is the main component of Portland cement (besides lime)?