CHAPTER 3 – MECHANICAL MIXTURES Grade 7 Science Presented on: February 17, 2011.
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Transcript of CHAPTER 3 – MECHANICAL MIXTURES Grade 7 Science Presented on: February 17, 2011.
SORTINGDEFINITION
Involves looking at various pieces and physically moving one or more of the pieces into different containers
This allows similar pieces to be put together
EXAMPLES
PizzaSaladLaundry
FLOATINGDEFINITION
Lighter component rises to the top of a liquid where it can be skimmed off
EXAMPLES
Melted chicken fat
SETTLINGDEFINITION
Heavier component sinks to the bottom of a liquid – the liquid can be poured off leaving the heavier component
EXAMPLES
Gold dustWaste water treatment
Blood
A device that is used by many labs is a CENTRIFUGE It is an equipment piece that holds
test tubes The test tubes are spun very quickly
causing the heavier component to sink quickly to the bottom
Device that can be used for Settling
CENTRIFUGE
MAGNETDEFINITION
Some metals and alloys (iron,steel) are attracted to magnets. If they are part of a mixture we can remove them using a magnet.
EXAMPLES
Scrap Metal Yard
A device that is used when there is a mixture with solid and liquid parts
This device has many visible holes that allow smaller solid pieces and liquids to pass through blocking large solid pieces
Device that can be used
SIEVE
SIEVINGDEFINITION
Process in which larger pieces of matter are separated out of the mechanical mixture
EXAMPLES
Pasta in Water using a colander
A device that is used to separate solids from liquids
This device has many small holes that trap solid pieces of a mixture but allow liquids and gases to pass through.
Device that can be used
FILTER
FILTRATIONDEFINITION
Mixture passes through a filter to separate solid pieces from a liquid or gas
EXAMPLES
Pepper in Water
1. You will be working in groups – each group will have a letter
2. Each group will get two cups, salt/pepper mixture, filter paper
3. Each group member will have a role – number yourselves 1 to 4.
4. Group Member One: Will go to the side and grab one cup with their group letter which has 50mL of water.
5. Students will grab a small cup with salt/pepper mixture6. Group Member Two: Will mix the mixture and the water
using a popsicle stick7. Group will work together to try and separate the mixture.
EXPERIMENT