Which type of change is demonstrated by molecules rearranging to form a new substance? A. electrical change

B. physical change

C. chemical change

D. gravitational change

correct option is (c) chemical change

Yes, it is balanced because the number of atoms of each element was same for both reactant side and product side.

Explanation:

Atoms of elements combine with one another to form compounds in a process called chemical reactions. In this case, atoms of Aluminum (Al) combines with atoms of Oxygen (O) to form Aluminum oxide (Al2O3).

However, for a chemical reaction to obey the law of conservation of mass, it needs to be BALANCED. Being balanced, for a chemical reaction, means the number of atoms of each element on the reactant side must equal the ones on the product side. To do this, coefficients are used at the back of each elements.

The original equation looks like:

AI + O2 → AI2O3

To make this balanced, coefficients 4 and 3 were used at the back of Al and O2 respectively while coefficient 2 was used behind Al2O3 as follows:

4AI+3O2 → 2AI2O3

Hence, the equation provided in this question is already balanced because the number of atoms of each element was same for both reactant side and product side.