Why is"decomposition" a good name for these types of reactions?

Which fact represents evidence for the big bang theory?

For the reaction shown, find the limiting reactant for each of the following initial amounts of reactants. 4al(s)+3o2(g)→2al2o3(s) a) 1 molal, 1 mol o2 b) 4 molal, 2.6 mol o2 c) 16 molal, 13 mol o2 d) 7.4 molal, 6.5 mol o2

If you burn 46.6 g of hydrogen and produce 416 g of water, how much oxygen reacted