$CaCO_3$ was reacted with dil $HCl$ to form three products. One of the products formed,when passed into slaked lime,gave $X$. What is $X$?

Chemical $A$ is used for water softening to remove temporary hardness. $A$ reacts with $Na_2CO_3$ to generate caustic soda. When $CO_2$ is bubbled through $A$,it turns cloudy. What is the chemical formula of $A$?

Deep pink colour is given to flame by the salts of

Correct order of density in $IIA$ group (alkaline earth metals) is:

The composition formula of gypsum is

Write a note on: anomalous behavior of beryllium compared to other alkaline earth metal elements.