Which alloy is used to solder electric wires?

Which of the following elements will form an acidic oxide?

An element $A$ reacts with water to form a compound $B$ which is used in white washing. The compound $B$ on heating forms an oxide $C$ which on treatment with water gives back $B$. Identify $A$,$B$ and $C$ and give the reactions involved.

Which non-metal element is used in the vulcanization of rubber?

Which metal does not react even with hot water or steam?

Which among the following statements is incorrect for magnesium metal?