Given the unbalanced equation: Al + O2 → Al2O3 When this equation is completely balanced using smallest whole numbers, what is the sum of the coefficients?

The sum of the coefficients is 9.

Step-by-step explanation:

A chemical equation shows the chemicals that react (the reactants) followed by an arrow followed by the chemicals that are produced by the reaction (the products).

We have the following unbalanced equation

To balance an equation, we add a coefficient to the front of each element or compound that requires it. Essentially you are multiplying the amount of atoms or compounds on one side to match the amount on the other side.

The balanced chemical equation is

The sum of the coefficients is equal to the sum of the number of reacting molecules and the number of products produced in the balanced chemical equation.

Therefore,

4 + 3 + 2 = 9