Question

Which would have coarser grains, intrusive or extrusive rock? Why? What about lava/magma?

a) Intrusive has coarser grains; magma has fine grains.
b) Extrusive has coarser grains; lava has fine grains.
c) Intrusive has fine grains; magma has coarser grains.
d) Extrusive has fine grains; lava has coarser grains.

Answer 1

Extrusive igneous rocks are fine grained, while intrusive igneous rocks are coarse grained.

correct answer is D

Step-by-step explanation:

Extrusive igneous rocks cool quickly and as a result, these rocks are fine grained.

On the other hand, intrusive igneous rocks are formed from magma that cools slowly and as a result, these rocks are coarse grained.

correct answer is D