What is iron coated with a layer of zinc called?

Explain the following:
$(a)$ $NaCl$ is not a conductor of electricity in solid state,whereas it does conduct electricity in aqueous solution as well as in molten state.
$(b)$ Iron articles are galvanised.
$(c)$ Metals like $Na, K, Ca$ and $Mg$ are never found in their free state in nature.

State whether the following statement is true or false:
Non-metals react with acids to produce a salt and hydrogen gas.

Give the composition of the alloys brass and bronze.

Which non-metal element is a conductor of electricity?

$Al_{2}O_{3(s)} + 2NaOH_{(aq)} \xrightarrow{\Delta} \dots + H_{2}O_{(l)}$