Holme's signals can be obtained by using

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 given orders is not correct?

Choose the correct order.

Assertion : $Al(OH)_3$ is insoluble in $NH_4OH$ but soluble in $NaOH$.
Reason : $NaOH$ is a strong alkali.

The two major constituents of Portland cement are