How many COMMON crystalline structures for metals are there?
1
4
2
3

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.

56 moles of   lieter in chemistry

d

explanation:

it's c (engineer's do their work with mechanical stuff not on any living being)