I hate stoichiometry. I will help you but I need to know the question first.
Explanation:
Moles of N2 = 84/28 = 3.0mol
Moles of H2 = 29/2 = 14.5mol
Hence amount of ammonia produced = 6.0 * 17 = 102g.
Im pretty sure it weight because when we are on different plants with a different amount of gravitational pull our weight changes
hope this helps :)