It would be plastic Becaus we can recreate things with plastic and other things that are recyclable. Since,we mostly cut down trees everyday for paper,not knowing that we are wasting natural resources, and destroying animal homes and food.
The answer to your question is : no.of moles of Si = 43/atomic mass of Si = 43/28.1 = 1.53
according to reaction 3 moles of Si gives 1 mole of Si3N4
so 1.53 mole of Si will give 1.53/3 = 0.51 mole of Si3N4
molar mass of Si3N4 = 140.28 g/mole
it means that 1 mole of Si3N4 = 140.28 g
so 0.51 mole of Si3N4 = 0.51 X 140.28 = 71.543 g
2.5×103 and 3.5 x 102=6.0x103