4.2 - Physical and Chemical...
Transcript of 4.2 - Physical and Chemical...
4.2 - Physical and Chemical Properties
Physical Properties
A physical property is a characteristic or description of a substance thatmay help to identify it. This characteristic can be observed or measured.
An observed property is called qualitative. A measured property is calledquantitative.
There are 10 common physical properties of matter that can be usefulwhen describing or identifying different substances.
How many can you think of?
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1. Colour and lustre (shininess)2. Melting point
(1) (2)
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1. Colour and lustre (shininess)2. Melting point
(1) (2)
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3. Boiling point
(3)
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3. Boiling point
(3)
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4. Density - amount of mass in a substance per a certain volume5. Solubility - ability to dissolve in water
(4) (5)
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4. Density - amount of mass in a substance per a certain volume5. Solubility - ability to dissolve in water
(4) (5)
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6. Ductility - a solid that can be stretched/rolled7. Texture
(6) (7)
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6. Ductility - a solid that can be stretched/rolled7. Texture
(6) (7)
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8. Hardness - a substance’s ability to resist being scratched9. Malleability - a substance that can be pounded or rolled
(8) (9)
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8. Hardness - a substance’s ability to resist being scratched9. Malleability - a substance that can be pounded or rolled
(8) (9)
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10. Conductivity - ability to conduct electricity
(10)
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10. Conductivity - ability to conduct electricity
(10)
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Chemical Properties
Chemical property - a characteristic behaviour that occurs when asubstance changes to a new substance.
There are 4 common chemical properties.
How many can you think of?
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Toxic - substances that even insmall quantities may poison, causeinjury or death when swallowed,absorbed through the skin, orinhaled into the lungs.
Flammable - substances, usuallyliquids, that can readily ignite (burnin air) in a wide range oftemperature conditions.
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Corrosive - substances or vapoursthat can deteriorate or eat away thesurface of another material.
Reactive/Explosive - substancesthat can react with air, water, oranother substance to produce toxicvapours or explode.
Watch: “Sodium in Water”
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Physical Change
Physical Change - a change in the size or form a substance which doesnot change the chemical properties.
Freezing - liquid to solid
Melting - solid to liquid
Boiling - liquid to gas
Condensation - gas to liquid
Sublimation - solid to gas
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Chemical Change
Chemical change - the formation of a new substance.
Signs of a chemical change:
Gas is produced
Colour change
Difficult to reverse
Heat or light is given off
Solid is formed
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Review Questions
1 What is a physical property?
2 For each of the following substances, list four physical properties.
wateriron metalbaking soda
3 What is a chemical property? List three examples of chemicalproperties.
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