Question

How is continental crust different from oceanic crust?

Answer 1

The question is asking to answer the following questions and base on my further research and investigation, I would say that answer would be the following: 
#1 D. Oceanic crust is thinner and less dense than continental crust.
#2 B.  where an oceanic plate is moving toward a continental plate
#3 A. The seafloor is spreading.

Answer 2

Answer:

1- Option (C)

2- Option (B)

3- Option (A)

Explanation:

The continental crust is thick and is about 35 to 40 km on an average and is comprised of less denser granitic rocks that contains minerals such as quartz and feldspar. But, oceanic crust is thin and about 7-10 km on an average and are comprised denser basaltic rocks containing minerals such as pyroxene, olivine and alkali feldspar. Thus, the oceanic crust are thinner and denser than the continental crust.

In a convergent plate boundary, when an oceanic plate move towards the continental crust, the denser oceanic crust sinks below the lighter plate, as a result of which it forms a subduction zone that is marked by the trench. It generates deep-focus earthquakes and also forms volcanoes on the over-riding plate.

Seafloor spreading refers to the separation of the oceanic plate along the mid oceanic ridge, which results in the enlargement of the ocean basin and leads to the addition of new materials to the crust. It occurs in a divergent plate motion.

Thus, the correct answers are matched above.