Chapter 4: Structure and properties of materials

Chapter 4: Structure and properties of materials

By Angela Odong

• A property that is seen when a substance takes part in a chemical change.

• Example: reactivity, flammability

Chemical Properties

• properties that can be observed or measured.

• Example: Hardness, boiling point, melting point, electrical conductivity, thermal conductivity, solubility and density.

Physical Properties

Physical and chemical properties

Open TB pg 75

4.2 Acidity and indicators

both substance can harm you, it can burn our skin.

Litmus paper is red in acid and blue in alkalis.

Litmus

Used to measure how strongly acid or alkaline on the pH scale.

​pH 1-3 Strong acid

pH 4-6 Weak acid

pH 7 Neutral

pH 8- 10 weak alkaline

pH 11- 14 strong alkaline​

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Universal indicator

​Indicators