$A$ salt gives a bright red colour to the flame. This colour indicates the presence of:

From which of the following is the hydration energy of $Mg^{2+}$ larger?

$BaSO_4 + C \rightarrow A + CO$
In the above reaction,$A$ is:

The setting time of cement is increased by adding which of the following?

Given below are two statements:
Statement $I$: None of the alkaline earth metal hydroxides dissolve in alkali.
Statement $II$: Solubility of alkaline earth metal hydroxides in water increases down the group.
In the light of the above statements,choose the most appropriate answer from the options given below:

Why does the solubility of alkaline earth metal hydroxides in water increase down the group?