- You might see rocks in a cliff face or mountainside, but these are also rocks under the ground. Marble is one can you name two more?
- Does water flow more quickly through sandy soil or clay soil?
- Particles are arranged differently in solids and in liquids. Summarise these differences in a couple of sentences.
- The pH scale describes how acidic or alkaline a solution is. Neutral solutions have pH 7. What is sort of pH does a weak acid have.
- If you leave a bowl containing a solution of a salt in water, the water disappears, leaving the salt behind. Where has the water gone
- A rock is a mixture of minerals that occur naturally in the Earth's crust.
- Rocks have different textures depending on how their mineral particles are arranged. Some rocks are porous - they have little spaces in their structure which can hold water.
- Rocks can be worn away or weathered by conditions in the environment. Physical, chemical and biological processes wear away rocks. Changes in temperature can weather rocks physically. The acid in rain water can react with rocks and wear them away chemically.
- Weathered fragments of rocks are transported away from where they fall. Sediments carried by water can be dropped or deposited many miles away.
- Layers of sediments may be deposited on top of each other and become cemented together to form new sedimentary rock.
- The earth has a central part called the CORE which is made of iron and a bit of nickle. The core is very hot.
- Around the core is a hot semi-liquid rock layer called the MANTLE.
- Covering the mantle is a cooler solid surface that we live on called the CRUST.
- Minerals are solid substances that make up the earth's crust.
- Have a definite composition,a regular structure and more often a single colour.
- Most minerals are compounds,a few are elements.
Rocks
- A rock is a mixture of minerals.
- The minerals are in grains
- In some rocks the grains are large and you can see them.
- If a rock has a mixture of grains it might look multi-coloured or speckled.
- Other rocks are crystalline.They have smooth faces which reflect light and so appear shiny.the grains have formed crystals that fit together so you can,t see the individual grains.
Classifying rocks
Properties used to identify rocks
- Colour
- Hardness
- texture
- how they split up when hit(cleavage)
- Chemical behaviour
- The easiest way to classify rocks is by where they come from.
- This splits rocks into 3 different types
These are formed when the molten rock inside the Earth cools and solidifies.
