$A$ white solid '$A$' on heating gives off a gas which turns lime water milky. The residue is yellow when hot but turns white on cooling. This solid '$A$' is

Among the alkaline earth metals ($Be$,$Mg$,$Ca$,and $Sr$) of group $IIA$,which one forms an ionic chloride?

Which of the following has the highest enthalpy of hydration?

Which of the following statements is incorrect?

Slaked lime $[Ca(OH)_2]$ is used in the manufacture of:

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 ......