Which substance is formed when ammonia gas reacts with hydrogen chloride gas?

Give reasons for the following:
$(i)$ Carbon can reduce zinc oxide to zinc but not calcium oxide to calcium.
$(ii)$ Copper and aluminium wires are usually used for electricity transmission.

Which gas has the potential to become a major energy source in the future?

Which of the following methods is suitable for preventing an iron frying pan from rusting?

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

$(i)$ Name a metal which does not stick to glass.
$(ii)$ Name the metal which is commonly used in thermite welding.
$(iii)$ What is the nature of zinc oxide?