how many grams of Fe are needed to react with 8.0g of O2 to produce 28.9 g of Fe3O4 according to the equation 3Fe+2O2—> Fe3O4

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

the maximum mass of nh3 is nh3 in grams

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