The following reactions (note that the arrows are pointing only one direction) can be used to prepare an activity series for the halogens:
Br₂(aq) + 2NaI(aq)→2NaBr(aq) + I₂(aq)
Cl₂(aq) + 2NaBr(aq)→2NaCl(aq) + Br₂(aq)

(a) Which elemental halogen would you predict is the most stable, upon mixing with other halides?

(b) Predict whether a reaction will occur when elemental chlorine and potassium iodide are mixed.

(c) Predict whether a reaction will occur when elemental bromine and lithium chloride are mixed.