Balance this equation, Al_(2)O_(3)... Al+O_(2) underline (2)Al_(2)O_(3)... underline (2)Al+underline (3)O_(2) underline (2)Al_(2)O_(3)... underline (4)Al+underline (3)O_(2) Cannot be balanced underline (3)Al_(2)O_(3)... underline (2)Al+O_(2)

The correct answer is: $\underline {2}Al_{2}O_{3}\cdots \underline {4}Al+\underline {3}O_{2}$<br /><br />Explanation: To balance the equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation. In this case, we have 2 molecules of $Al_{2}O_{3}$ on the left side, which means we have 4 atoms of Al and 6 atoms of O. On the right side, we have 4 atoms of Al and 3 molecules of $O_{2}$, which means we have 6 atoms of O. Therefore, the balanced equation is $\underline {2}Al_{2}O_{3}\cdots \underline {4}Al+\underline {3}O_{2}$.