Sulfur dioxide - Wikipedia
Sulfur dioxide is found on Earth and exists in very small concentrations and in the atmosphere at about 1 ppm. [clarification needed]On other planets, sulfur dioxide can be found in various concentrations, the most significant being the atmosphere of Venus, where it is the third-most abundant atmospheric gas at 150 ppm.There, it reacts with water to form clouds of sulfuric acid, and is a key