Which alloy is used to solder electric wires?

State the conditions under which the following metals react with water. Write the equation for each reaction:
$(a)$ $Na$
$(b)$ $Mg$
$(c)$ $Fe$

Which one of the following properties is not generally exhibited by ionic compounds?

Which metal does not react with cold or hot water,but reacts with steam to produce $H_2$ gas?

$(a)$ What type of ores are calcined? Illustrate by giving a suitable example.
$(b)$ In what form is the calcined ore obtained,and how can it be reduced? Give chemical equations of the reduction process involved for the example provided by you.
$(c)$ Name two metals used as reducing agents by displacing metals of lower reactivity from their compounds.

Which compound is formed when dinitrogen gas reacts with dihydrogen gas?