Step-by-step explanation:
![Al_2O_3\rightarrow Al+O_2](https://img.qammunity.org/2020/formulas/chemistry/high-school/369t8zuatqsqnttz40w2c4bwsgzdm59xbr.png)
Number of aluminum atoms the reactant side = 2
Number of oxygen atoms the reactant side = 3
Number of aluminum atoms the product side = 1
Number of oxygen atoms the product side = 2
Since, given reaction is not balanced chemical reaction:
So, the balanced chemical reaction is given by:
![2Al_2O_3\rightarrow 4Al+3O_2](https://img.qammunity.org/2020/formulas/chemistry/high-school/t3qe65sa9pr7jk6it671qsnxvmrt1budbb.png)
According to reaction,2 moles of aluminum oxide gives 4 moles of aluminum and 3 moles of oxygen gas.