Answer:
Let's break it down:
1. You have 10.4 grams of oxygen and 10.4 grams of aluminum.
2. We mix them together to make aluminum oxide (a type of powder).
3. We need to figure out which one runs out first because we can't make more aluminum oxide than what the smaller amount of reactant allows.
4. Oxygen runs out first.
5. We use up all the aluminum to make as much aluminum oxide as we can.
6. With the given amounts, you can make about 19.66 grams of aluminum oxide.