My science revision guide

My science revision guide

Sedimentary rock

KEY WORDS

sedimentary- rock made from sediments

Igneous- Rock made when liquid rock (magma or lava) cools and freezes

Metamorphic- rock formed the action by the action of heating and/or pressure on sedimentary or igneoue rock 

porous- A porous material has small gaps that may contain substances in their liquid or gas states water can soak into a porous material

weathering- weathering breaks up all types of rock into smaller pieces,called sediments

A Name three groups of rock

sedimentary rock

igneous rock

metamorphic rock

B Describe three properties of sedimentary rock

Sedimenatary rock are made up of seperate grains.you can see these with a hand lens

sedimentary rocks are porous.they have gaps between their grains.air or water can get into these gaps

most sedimentary rocks are soft.you can scratch them easily

C list four stages in making sedimentary rock

Weathering 

weathering breaks up all types of rck into smaller pieces called sediments.there are different types of weathering

physical weathering

chemical weathering

biological weathering

erosion and transport

Next sediments move away from their rock.together the breaking of rock into sediments and their movement away,is called erosion

transport processes move sediments far from the original rock.water,ice,wind and gravity can move all sediments

deposition

eventually,sediments stop moving.they settle in one place.this is deposition.layers of different types of sediment may settle on top of each other

compaction and cementation

over many years deposited sediments join together to make new rocks this happens by

compaction- the weight of sediments above squashes together the sedimetns below or

cementation- another substance sticks the sediments together

Exothermic and endothermic

KEY WORDS

endothermic change- an endothermic change transfers energy from the surroundings

exothermic change- an exothermic change transfers energy to the surroundings

A state what an endothermic change is 

The process in the cold pack is an endothermic change.the surroundings transfer energy to substances is an endothermic change.some chemical reactions are endothermic.melting and boiling are also endothermic.so is the formatio of some solutions

Indicators and pH

KEY WORDS

indicator- a substance that changes colour to show whether a solution acidic or alkaline

litmas- an indicator.Blue litmus paper goes red on adding acid.red litmus paper goes blue on adding alkali

universal indicator- An indicator that changes colour to show the pH of a solution.it is a mixture of dyes

pH scale- the pH scale shows whether a substance is acidic,alkaline or neutrel.An acid has a pH below 7.An alkaline solution has a pH above 7.A solution of pH 7 is neutrel

neutrel- A solution that is neither alkaline nor acidic,its pH is 7

A state what an indicator is

an idicator contains a dye.the dye turns a different colour in acidic and alkaline solutions

B state the colour change when a student add an acid to blue litmas paper

Litmus is a solution of dyed from lichens.red litmus paper turns blue of ading alkali.blue litmus paper turns red on adding acid

C state the pH of a neutrel solution

the pH of a neutrel solution is exactly 7

Acids…