Observe the following compounds.
$(i)$ $CaCO_3$
$(ii)$ $MgSO_4$
$(iii)$ $BaCl_2$
$(iv)$ $Sr(NO_3)_2$
$(v)$ $MgBr_2$
$(vi)$ $MgCl_2$
The oxoacid salts of group $II$ elements from the above list are

The thermal stability of $MCO_3$ (where $M$ is an alkaline earth metal) follows the order:

Which of the following is different from the other three oxides?

$X + C + Cl_2 \xrightarrow{1000 \ K} Y + CO;$
$Y + 2H_2O \rightarrow Z + 2HCl$
Compound $Y$ is found in a polymeric chain structure and is an electron-deficient molecule. $Y$ must be:

Which of the following elements has the highest tendency to form a peroxide?

Fill in the blanks:
$(1)$ Calcium oxide is commonly known as .......
$(2)$ $A$ suspension of calcium hydroxide in water is known as ....
$(3)$ The common name of calcium hydroxide is .......
$(4)$ The general name of calcium sulphate hemihydrate is ......