Solid lithium and iodine gas are formed by the decomposition of solid lithium iodide.

Write a balanced chemical equation for this reaction.

Lithium Iodide is

LiI

Lithium has a charge of 1+, and Iodide has a charge of 1-, thus this is the correct form.

Remember Iodine is Diatomic when it is alone! So I_2

LiI (s) - > Li (s) + I_2 (g)

Is the formula you get when you simply write it out, but now we need to balance it.

1 Lithium, 1 Iodide - > 1 Lithium + 2 Iodine

We need 2 Iodine on the left side, so we can add coefficients to the left to create that balance.

2 (1 Lithium, 1 Iodide) - > 1 Lithium + 2 Iodine

is the same as ...

2LiI - > Li + I_2

Now we have to balance the Lithiums on the right ... so our final balanced equation is:

2LiI - > 2Li + I_2

(Note that the _2 is a subscript of 2)