Subject : BASIC TECHNOLOGY
Term : FIRST TERM
Week: Week 8
Class : JSS1
Previous lesson :
The pupils have previous knowledge of IDENTIFICATION OF METALS(II)
IDENTIFICATION OF CERAMICS & GLASSES
Behavioural objectives :
At the end of the lesson, pupils would have learnt
- different types of ceramics
- Definition and Properties of glasses
- Classes of ceramics
- Processing of glass
- Uses of ceramics
Instructional Materials :
- Wall charts
- Related Online Video
- Flash Cards
Methods of Teaching :
- Class Discussion
- Group Discussion
- Asking Questions
- Role Modelling
- Role Delegation
Reference Materials :
- Scheme of Work
- Online Information
- 9 Year Basic Education Curriculum
Clay exists naturally in many parts of the world. When it is wet, it can easily be molded into different shapes and sizes. We use clay to mould various objects like storage pots, cooking pots and dishes.
We use mud to construct support for cooking pots, to build houses and also to make bricks for building houses. We make cement blocks that we use for building houses by mixing sand and cement to get typical shape. All the above solid objects made from clay, mud or cement are called ceramics.
Ceramics break easily when dropped. We say they are brittle, this differentiates ceramics from metals, plastics, wood and rubber. Ceramics are less dense than most metals. Ceramics have high melting points.
Classification of Ceramic materials
Ceramic materials are classified based on the types of materials used in making them. They are;
- The clay materials: These include: objects like age pot, dishes, and cups.
- The mud materials: These are used to construct support for king pots, make bricks for building houses.
- The cement materials: These are mixture of cement, sand and water for molding blocks use for building houses.
Properties of Ceramics
- They are brittle: They can easily break into pieces.
- They can easily be molded.
- They can withstand very high temperature.
- They have resistance to heat.
- They are malleable when mixed with water.
- They are resistance to corrosion.
- They have high melting point
- Ceramic materials and properties
- Glass materials and properties
CERAMIC MATERIALS AND PROPERTIES
Ceramic is a hard brittle heat-resistant material made by firing a mixture of clay and chemicals at high temperature. The ceramic products are products made from clay and chemical materials.
Examples are clay pots, marbles, tiles , water-closet, water-jug, glass , water basins etc.
PROPERTIES OF CERAMIC MATERIALS
- Ceramics are resistant to corrosion.
- They can withstand very high temperature e.g. furnace and oven.
- They are electrically resistant.
- They are usually hard and strong.
- They have compressive strength.
- They can easily be molded when wet.
- They can easily break when dropped on the ground.
- What is a ceramic?
- List five properties of ceramics.
GLASS MATERIALS AND PROPERTIES
Glass is a type of ceramic. Glass is a hard usually transparent material made from sand, lime, potash, soda and lead oxide. To produce glass, these raw materials are mixed and placed in a furnace and melted. It is then formed into the desired objects.
Making of glass involves the following stages:
- Mixing the raw materials;
- Heating (firing) to produce molten glass;
- Cooling to form rigid glass;
- Heating again and allowing to cool gradually (annealing).
PROPERTIES OF GLASS
- It is brittle,
- It is transparent and
- Resistant to corrosion.
Examples of glass products are cups, bottles, mirrors, glass tubes, electric bulbs, glass window, glass doors, eye glasses and lenses.
- What are the materials for making glass?
- List three properties of glass.
- Which of the following is not used in making glass?
- Sand (b) lime (c) potash (d) clay
- Glass is used to manufacture eye glasses and lenses because of this property. Choose from the options. (a) Brittleness (b) resistance to corrosion (c) transparent (d) resistance to heat.
- Which of the following is not used in making ceramics? (a) lime (c) cement (c) mud (d) clay.
- The following are products of ceramics, except (a) flower vase (b) tiles (c) wash basin (d) electric bulb.
- What are ceramics and glass?
- List two differences between the two.
The topic is presented step by step
The class teacher revises the previous topics
He introduces the new topic
The class teacher allows the pupils to give their own examples and he corrects them when the needs arise
The lesson is concluded when the class teacher wraps up the lesson by giving the pupils some notes.
The class teacher also goes round to make sure that the notes are well copied or well written by the pupils.
He or she does the necessary corrections when and where the needs arise.
Prepare for the next lesson by reading about Properties of materials – RUBBER
(Visited 523 times, 1 visits today)