Ammonia (nh3) is widely used as a fertilizer and in many household cleaners. how much ammonia is produced when 6.44 mol of hydrogen gas react with an excess of nitrogen gas?

The answer would be the Chemical formula for ammonia by hydrogen and nitrogen gas: 1 N2 + 3 H2 --> 2 NH3 then use stoichiometry. You know you have enough nitrogen gas to react, so you can just straight convert mol H2 to mol NH3, where 3 mol H2 = 2 mol NH3. 
3.44 mol H2 * (2 mol NH3 / 3 mol H2) = 2.29 mol NH3

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).