In the synthesis reaction where two atoms of sodium (Na) combine with one molecule of chlorine gas (Clâ‚‚) to produce sodium chloride (NaCl), the balanced chemical equation is:
\[ 2 , \text{Na} + \text{Cl}_2 \rightarrow 2 , \text{NaCl} \]
From this equation, we see that 2 sodium atoms react with 1 molecule of chlorine gas to produce 2 molecules of sodium chloride. Therefore, the reaction produces 2 molecules of sodium chloride (NaCl).