Consider the reaction na+(g) + cl−(g) → nacl(s). if the temperature is lowered, what is favored? 1. products 2. reactants

Answer is: 1. products (NaCl(s)).
This reaction is exothermic, which means that heat is released. According to Le Chatelier's principle when the reaction is exothermic heat is included as a product and when the temperature decreased, the heat of the system decreases, so the system consume shifting the equilibrium to the right,  producing more sodium chloride.

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab.