in a tool shed, you found an old pile of aluminum that reacted with oxygen creating aluminum oxide. you wondered, how much did the aluminum weigh before it reacted with oxygen? As a chemistry student, you weighed out the aluminum oxide and found it to be 8.50 grams.
1. 4 Al (s) + 3 O2 (g) = 2 Al2O3 (s)

2. What was the original mass of aluminum?