What are Rocks?
Geography: KS3, topic 7.1.1
What are Rocks?
Rocks are solids (at room temperature) and are made up of tiny grains that together, form a rock. Rocks can form in different ways and so have different properties, e.g. whether or not they are porous.
Porous rocks
- Porous rocks absorb water.
- Porous rocks are also usually softer- they erode more easily.
- This is because there are tiny gaps between the grains in the rocks and water is able to pass between these gaps.
Non-porous rocks
- Non-porous rocks do not absorb water.
- Non-porous rocks are usually hard- they erode less easily.
- This is because the grains in the rock are interlinked which means that water (and other substances) cannot pass between the rocks.