1. which of the following is true of oceanic plates? a. they are perfectly flat and smooth. b. they formed before other types of plates. c. they are heavier than continental plates. d. they move more often than continental plates. 2. where can magma be found on the surface of the earth? a. in active volcanoes b. underneath lakes and rivers c. in between all continental plates d. in the afermath of an earthquake 3. convergent plate mmvement can create all of the following except a. ridges b. valleys c. mountains d. volcanoes

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.  

i i think it might b c