Diversity of Matter: Its Physical Properties

Objectives

• Understanding physical properties.
• Learn about units of measurement.
• Know the SI units for various physical properties.

Physical Properties of Materials

Physical properties are qualities that can be detected with our senses or measured with devices.

1. Flexibility

• Definition: Ability to bend without breaking and return to original form.
• Example: Rubber band.

2. Hardness

• Definition: Ability to withstand scratches.
• Example: Diamond, which is the hardest material, cuttable only by another diamond.

3. Melting Point

• Definition: Temperature at which a solid turns to liquid.
• Example: Water's melting point is 0°C.

4. Boiling Point

• Definition: Temperature at which a liquid turns to gas.
• Example: Water's boiling point is 100°C.

5. Strength

• Definition: Ability to support heavy loads without tearing or breaking.
• Example: Metal car frames.

6. Thermal Conductivity

• Definition: Measure of heat transfer through a material.
• Good Conductors: Metals.
• Poor Conductors: Rubber, glass, plastic.

7. Electrical Conductivity

• Definition: Ability for electricity to pass through a material.
• Conductors: Metals.
• Insulators: Non-metals.

8. Density

• Definition: Quantity of matter per unit volume.
• Concept: Denser materials sink in less dense liquids; less dense materials float in denser liquids.

Units of Measurement

• Measurements consist of numeric value and unit.
• Example: Length is measured as 12 cm, where 12 is the value and cm is the unit.

SI Units

Table of Common SI Units:

• Length: metre (m)
• Mass: kilogram (kg)
• Temperature: Kelvin (K)
• Time: second (s)

Mass

• Definition: Amount of matter in an object.
• SI Unit: Kilogram (kg).
• Instruments: Electronic balance, triple-beam balance, four-beam pan balance.

Length

• Definition: Distance between two points.
• SI Unit: Metre (m).
• Instruments: Measuring tape, metre rule, Vernier caliper.

Volume

• Definition: Amount of space an object occupies.
• SI Unit: Cubic metre (m³).
• Instrument: Measuring cylinder for liquids.

Revision Questions

1. Identify non-physical property: happiness.
2. Ability to support heavy loads: strength.
3. Ability to bend without breaking: flexibility.
4. Ability to withstand scratches: hardness.
5. SI unit of temperature: Kelvin.
6. SI unit of length: metres.

Test Yourself

• Understanding the strength of a material: Ability to support a heavy load.

Importance of Environmental Conservation

• Reasons: Limited natural resources, maintain species diversity, reduce waste.

Experimentation and Testing

• Example: Testing electrical conductivity using a bulb and liquid.

Instruments for Measurement

• Length: Vernier caliper.
• Mass: Electronic balance.

This summary covers key points about the diversity of matter based on its physical properties and includes practical applications and measurements using SI units.