The correct order of melting point for alkaline earth metals is:

Epsom salt is a hydrate of which of the following?

Which is used to reduce the acidity of soil?

Identify the correct statements from the following.
$(A)$ $BeSO_4$ is soluble in water.
$(B)$ $BeO$ is an amphoteric oxide.
$(C)$ $CO$ can be obtained by heating $CaCO_3$ at $1070-1270 \ K$.

Fill in the blanks:
$(1)$ Cement is also known as......
$(2)$ Cement was first introduced by......

How would you explain the following observations?
$(i)$ $BeO$ is almost insoluble but $BeSO_4$ is soluble in water,
$(ii)$ $BaO$ is soluble but $BaSO_4$ is insoluble in water,
$(iii)$ $LiI$ is more soluble than $KI$ in ethanol.