What is the difference between primary and secondary succession

A Primary succession happens following an opening of a pristine habitat, an example of this is a lava flow, an area left from retreated glacier, or abandoned strip mine. In contrast, secondary succession is a response to a disturbance, an example of this is a, forest fire, tsunami, flood, or an abandoned field.

gasoline is a mixture. it contains several different kinds of compounds that can be present in a variety of ratios.