Chinese names chemical compounds transparently:
二 (two) +
氧化 (-oxide) +
硫 (sulfur) = sulfur dioxide. The template works for many molecules:
一氧化碳 (CO, carbon monoxide),
二氧化碳 (CO₂, carbon dioxide),
二氧化硅 (SiO₂, silicon dioxide). Count the oxygens, then name the element.
