Alkaline earth metals belong to which group of elements?

$A$ metal $M$ readily forms a water-soluble sulphate and a water-insoluble hydroxide $M(OH)_2$. Its oxide $MO$ is amphoteric,hard,and has a high melting point. The alkaline earth metal $M$ must be

Which of the following has the lowest solubility?

Choose the correct statement from the following:
$(i)$ Beryllium is not readily attacked by acids because of the presence of an oxide film on the surface of the metal.
$(ii)$ $BeO$ is an amphoteric oxide.
$(iii)$ Beryllium exhibits coordination number more than four.
$(iv)$ Beryllium oxide is purely acidic in nature.

What is the basic composition and origin of cement?

$A$ pair of substances which gives the same products on reaction with water is