Answer:
1 c. They are heavier than continental plates
2 a. in active volcanoes
3 b. valleys
Explanation:
1. The oceanic plates is more denser than the continental plates because of the kind of rocks that dominate the plate . The oceanic plates contains more of Mafic rocks like basalt (Fe, Mg, Ca, low SiO2 ) that are heavier than the dominants rocks found in continental crust which are granitic (Na, K, Al, SiO2 )
2. Magma are usually a semi liquid or liquid rocks found underneath the earth .Magma's are usually found on the surface of the earth in a active volcanoes. When this magma flow on the surface of the earth it is called a lava.
3 convergent plate movements is simply define as the collision or coming together of various plates of the earth. it can exist ;
Divergent plate margin usually create rift valley because of how the plates move away from each other.