Which geographic features are associated with a divergent boundary?
hydrothermal vents
continental mountains
ridges
subduction trench
rifts

Most divergent plate boundaries are underwater (Iceland is an exception) and form submarine mountain ranges called oceanic spreading ridges. While the process is volcanic, volcanoes and earthquakes along oceanic spreading ridges are not as violent as they are at convergent plate boundaries.

r just means there's a number of carbon in teh chain. for example rcooh means that after x number of carbon, the chain ends with cooh.

explanation: