CHAPTER 3 – MECHANICAL MIXTURES Grade 7 Science Presented on: February 17, 2011

Elements and Compounds Minds On MATTER Mixture Mechanical Mixture Solutions Substance Elements and Compounds Compounds

3.2 – Separating Mechanical Mixtures

SORTING DEFINITION EXAMPLES Pizza Salad Laundry 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 Pizza Salad Laundry

FLOATING DEFINITION EXAMPLES Melted chicken fat Lighter component rises to the top of a liquid where it can be skimmed off Melted chicken fat

SETTLING DEFINITION EXAMPLES Gold dust Waste water treatment Blood Heavier component sinks to the bottom of a liquid – the liquid can be poured off leaving the heavier component Gold dust Waste water treatment Blood

Device that can be used for Settling CENTRIFUGE 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

MAGNET DEFINITION EXAMPLES Scrap Metal Yard Some metals and alloys (iron,steel) are attracted to magnets. If they are part of a mixture we can remove them using a magnet. Scrap Metal Yard

Device that can be used SIEVE 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

SIEVING DEFINITION EXAMPLES Process in which larger pieces of matter are separated out of the mechanical mixture Pasta in Water using a colander

Device that can be used FILTER 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.

FILTRATION DEFINITION EXAMPLES Mixture passes through a filter to separate solid pieces from a liquid or gas Pepper in Water

EXPERIMENT You will be working in groups – each group will have a letter Each group will get two cups, salt/pepper mixture, filter paper Each group member will have a role – number yourselves 1 to 4. Group Member One: Will go to the side and grab one cup with their group letter which has 50mL of water. Students will grab a small cup with salt/pepper mixture Group Member Two: Will mix the mixture and the water using a popsicle stick Group will work together to try and separate the mixture.