Which of the following is true of oceanic plates?

*They are perfectly flat and smooth.

*They formed before other types of plates.

*They are heavier than continental plates.

*They move more often than continental plates.

Option (3)

Explanation:

Earth's crust is divided into two types, namely the oceanic crust (plate) and the continental crust (plate). These plates move over the layer of the asthenosphere due to the convection current that generates in the mantle.

These oceanic plates are denser (heavier) than the continental plates because oceanic plates are comprised mainly of denser basaltic rocks that are rich in plagioclase feldspar and pyroxenes. When magma comes out at the mid-oceanic ridge on the ocean floor it forms lava.

Whereas continental plates are made up of silicate rocks, granitic rocks, and some feldspars and are less denser in comparison to the oceanic rocks.

Thus, the correct answer is option (3).

oceanic plates are heavier then other plates