Question

How do igneous rocks form?
Heat and pressure
Compaction and cementation of sediment
Evaporation of seawater
Cooling of molten lava or magma

Answer 1

Igneous rocks form from the cooling and solidification of molten lava or magma. When magma cools while still underground, it forms intrusive igneous rocks (like granite), and when lava cools on the Earth's surface, it forms extrusive igneous rocks (like basalt). Therefore, the correct answer is: **Cooling of molten lava or magma.**