Which of the following is not soluble in water?

Which of the following is dolomite?

Discuss the diagonal relationship between beryllium and aluminum metals.

The compound $A$ on heating gives a colourless gas and a residue that is dissolved in water to obtain $B$. Excess of $CO_2$ is bubbled through aqueous solution of $B$,$C$ is formed which is recovered in the solid form. Solid $C$ on gentle heating gives back $A$. The compound $A$ is:

Which element among the alkaline earth metals primarily forms covalent compounds?

Which of the following does not react with cold or hot water?