Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 => 8.72 mol
answer A
Its 470mg k dude or dudette
If you think of it endothermic is when there is energy needed for the reaction to occur and exothermic is when the reaction releases energy
