What are the constituents of solder alloy? Which property of solder makes it suitable for welding electrical wires?

Which of the following ores is in the form of oxide?

Why is sodium chloride soluble in water but not soluble in kerosene?

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

$2 \, mL$ each of concentrated $HCl$,$HNO_3$,and a mixture of concentrated $HCl$ and concentrated $HNO_3$ in the ratio of $3:1$ were taken in test tubes labeled as $A$,$B$,and $C$. $A$ small piece of metal was put in each test tube. No change occurred in test tubes $A$ and $B$,but the metal dissolved in test tube $C$. The metal could be:

Why is hydrogen gas not evolved when a metal reacts with nitric acid?