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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