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

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

3. 3.2 – Separating Mechanical Mixtures

4. 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

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

6. 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

7. 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

8. 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

9. 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

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

11. 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.

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

13. 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.