How many sulphur dioxide molecules are there in 1.80 mol of sulphur dioxide

Smog is the term used to describe the combination of fog and smoke

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

In which reaction is precipitation occurring?