Which of the following gases acts as a mild bleaching agent?

Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
$(i)$ Good thermal conductivity
$(ii)$ Good electrical conductivity
$(iii)$ Ductility
$(iv)$ High melting point

Which among the following alloys contains mercury as one of its constituents?

Which gas is highly soluble in water?

Which iron ore is reduced in a blast furnace to obtain iron metal?

Which of the following metals is used for making jewelry?