based on location in the periodic table, which element has chemical properties that are most similar to iodine

Iwill give extra points to who gets this right

Consider the reaction: n2(g) + o2(g) ⇄ 2no(g) kc = 0.10 at 2000oc starting with initial concentrations of 0.040 mol/l of n2 and 0.040 mol/l of o2, calculate the equilibrium concentration of no in mol/l how would this be done?

In which reaction is precipitation occurring?