What is the ratio of dihydrogen gas to dinitrogen gas used in the production of ammonia gas by Haber's process?

The metals which are mixed with iron to make stainless steel are:

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

$NH_{3}$ is used in the preparation of nitric acid by $.....$ process.

An element $A$ forms two oxides $AO$ and $AO_2$. The oxide $AO$ is neutral,whereas the oxide $AO_2$ is acidic in nature. Would you call element $A$ a metal or a non-metal?

During the extraction of metals,electrolytic refining is used to obtain pure metals.
$(a)$ Which material will be used as the anode and cathode for the refining of silver metal by this process?
$(b)$ Suggest a suitable electrolyte as well.
$(c)$ In this electrolytic cell,where do we get pure silver after passing an electric current?