That would be an endothermic reaction! :)
D. Atoms form millions of molecules. :)
Answer:
Sodium peroxide can be prepared on a large scale by the reaction of metallicsodium with oxygen at 130–200 °C, a process that generates sodium oxide, which in a separate stage absorbs oxygen: 4 Na + O2 → 2 Na2O. The ozone oxidizes the sodium to form sodium peroxide.
Hg(CO₃)₂ + 4AgCl → HgCl₄ + 2Ag₂CO₃