Question

1. balance the combination reaction between aluminum and iodine by dragging coefficients into the equation. ? al + ? i₂ → ? ali₃

Explanation:

Step1: Balance iodine atoms

On the right - hand side, there are 3 iodine atoms in $AlI_3$, and on the left - hand side, there are 2 iodine atoms in $I_2$. The least common multiple of 2 and 3 is 6. So, we put a coefficient of 3 in front of $I_2$ and a coefficient of 2 in front of $AlI_3$ to balance the iodine atoms. The equation becomes $Al+3I_2
ightarrow2AlI_3$.

Step2: Balance aluminum atoms

Now, on the right - hand side, there are 2 aluminum atoms in $2AlI_3$. So, we put a coefficient of 2 in front of $Al$ on the left - hand side. The balanced equation is $2Al + 3I_2
ightarrow2AlI_3$.

Answer:

$2Al+3I_2
ightarrow2AlI_3$ (coefficients are 2, 3, 2 respectively)