Book 12, Question 13
Why Does Lava Harden Into Different Rocks?
Lava hardens into different rocks depending on two things: what the lava is made of and how fast it cools. Think of it like baking, where ingredients and time both matter. Slower cooling gives crystals more time to grow.
More fun facts
- Igneous rocks form when magma cools underground or when lava cools at the surface.
- Volcanic rocks usually have tiny crystals or a glassy look because they cooled quickly when they erupted.
- Cooled igneous rock is tough and resists being worn away by water, ice and wind.
- Molten material is still called lava even after it cools and hardens.
- Volcanic rocks are found in at least 89 parts of the US National Park System.
Sources: BBC, National Park Service, Science News Explores
Questions kids ask
Why does fast cooling make tiny crystals?
Crystals do not have time to grow large when lava cools quickly.