Rocks and Weathering End of Topic

An igneous rock is a type of rock that forms from the solidification of molten rock material, such as lava or magma. It can be classified into two types: intrusive and extrusive, depending on where it solidifies. Intrusive igneous rocks form when magma cools and solidifies slowly beneath the Earth's surface, while extrusive igneous rocks form when lava cools and solidifies quickly on the Earth's surface.

A metamorphic rock is a type of rock that has been transformed from its original state by heat, pressure, or chemical processes. This transformation can occur due to changes in temperature and pressure deep within the Earth's crust, or as a result of contact with hot fluids or magma. Examples of metamorphic rocks include marble, slate, and gneiss.

A sedimentary rock is a type of rock that forms from the accumulation and cementation of sediment, which can include pieces of other rocks, minerals, and organic matter. Examples of sedimentary rocks include sandstone, limestone, and shale. They are carried by rivers as they begin to form.

• Hard

• Contain crystals

• Porous

Magma that has erupted and cooled quickly outside.

Magma that has cooled slowly deep underground.

• Layers

• Soft

• Porous

• Malleable

• Non-porous

• Hard

• Ductile

Where rocks break down. Weathering often leads to erosion which breaks down rocks even further. This makes them easier for wind and water to carry them away.

Water gets into the cracks of rocks. When the water freezes, it expands and the crack enlarges until it breaks apart.

Cracks form that are parallel to the surface. These rocks contract during the night and layers of rock begin to break off. This is also called onion skin weathering?

• Sulphur Dioxide (SO2) - released when sulphur impurities in coal react with oxygen

• Nitrogen Oxides (NOx) - produced from the reaction of nitrogen and oxygen in engines

The main rocks used to build houses are:

• Sandstone

• Limestone

• Slate tiles

Sandstone and limestone are sedimentary rocks. This makes them good for bricks as they are easy to cut but still hard enough to withstand things.

Slate is waterproof and can be split into many layers. It also doesn’t react to acid at all. THis maks it good for roofing tiles.

Rocks are usually too reactive to exist in the ground on their own, so instead they combine with other elements (usually sulphur or oxygen) to create a compound called an ore.

A few metals are so unreactive (gold and silver) that they are pure metals.

• Gold and silver are found in the ground and are so unreactive that they do not need further extraction.

• Most metals are found combined with other elements and therefore need to be separated. We do this with either displacement or electrolysis. This is where you use electricity to make a chemical change.

Polymers are substances made up of large molecules called ‘macromolecules’. These macromolecules are made up of smaller molecules called monomers. They make up the bases of many minerals.

A composite is a combination of two elements with different physical and chemical properties.

A ceramic is a material which is neither metallic nor organic. They are made of either metal or non-metal compounds which eventually harden.

the rock cycle is how rocks form.

• Start with magma. Metamorphic rocks are created over time with harsh pressure in magma below a volcano.

• Intrusive magma rocks are made inside magma too, however do not go through as much pressure and they end up cooling.

• When a volcano erupts, extrusive igneous rocks can alo be produced.

• Next, weathering and erosion occurs, and this is where sedimentary rocks form.

• This cycle continues.

Hydrocarbons. This means they contain both hydrogen and carbon. They burn very well which is why they are good as fuels.

• Plants die

• Layers eventually build up over them

• After millions of years of pressure, coal is produced.

• Plants and animals die

• Layers eventually build up over them

• After millions of years, oil is produced.