Rocks on another planet that appear to have formed from solidification of molten lava are most likely classified as which rock type?

Rocks on another planet that appear to have formed from solidification of molten lava are most likely classified as which rock type?

• A. Sedimentary
• B. Igneous
• C. Metamorphic
• D. Clastic

Answer: (B)

Rocks formed from the solidification of molten material are igneous rocks. When molten lava or magma cools, its atoms arrange into crystals, creating rock. If cooling happens quickly at the surface, you get fine-grained or glassy igneous rocks; slower cooling beneath the surface yields coarser igneous rocks. Sedimentary rocks come from deposited or precipitated materials, not from melt solidification, and metamorphic rocks form when existing rocks are altered by heat and pressure. Clastic describes a sedimentary texture made of fragments, not a rock formed from cooling lava.

Rocks formed from the solidification of molten material are igneous rocks. When molten lava or magma cools, its atoms arrange into crystals, creating rock. If cooling happens quickly at the surface, you get fine-grained or glassy igneous rocks; slower cooling beneath the surface yields coarser igneous rocks. Sedimentary rocks come from deposited or precipitated materials, not from melt solidification, and metamorphic rocks form when existing rocks are altered by heat and pressure. Clastic describes a sedimentary texture made of fragments, not a rock formed from cooling lava.