How long does it take, on average, for one centimetre of soil to form

The time needed to form a soil depends on the latitude: in environments characterized by a mild climate, it takes 200-400 years to form 1 cm of soil. in wet tropical areas soil formation is faster, as it takes 200 years. in order to accumulate enough substances to make a soil fertile it takes 3000 years.

Only one reactant yields 2 or more products. meaning you will only have 1 product and it will break down into 2 or more products. eg. h2o -> h2 + o2