9.2 Glass and Ceramic
Explore the composition, key properties, and practical applications of different types of glass and ceramic materials in daily life.
Learning Objectives
- State what glass and ceramic are made of.
- Identify four main types of glass, their chemical compositions, and their respective properties.
- Describe the physical and chemical characteristics of ceramics.
- Relate the properties of various types of glass and ceramics to their applications in daily life.
Summary of Glass Types and Ceramic Characteristics
Compare the components, properties and applications of the four types of glass alongside ceramic materials.
Short Explanation
What is Glass?
Silica is the main component of glass. Silica is a compound that contains silicon dioxide and exists naturally in sand. Pure silica melts and liquefies at around 1500°C to form glass.
What is Ceramic?
Ceramic consists of a non-metal substance formed from a heat reaction at a very high temperature. Its main raw material is clay, and its main component is aluminium silicate.
Glass and ceramic are durable, non-metallic materials designed to serve specific functional roles. By adding different metal oxides and compounds such as boron oxide, calcium carbonate, or lead(II) oxide to silica, manufacturers produce various types of glass suited for high thermal resistance, shaping flexibility, or optical brilliance. In contrast, ceramics are baked clay products composed of aluminium silicate, providing exceptional resistance to extreme temperatures, mechanical wear, and chemical attack.
Glass has been used since 5000 B.C. It is primarily made from silica found naturally in sand, whereas ceramic is made from clay containing aluminium silicate.
Types of Glass, Composition and Properties
Table 9.2 shows the four main types of glass and their characteristics.
| Type of glass | Composition | Properties |
|---|---|---|
| Fused silica glass | Silica | Resistant to heat, chemically inert. |
| Soda-lime glass | Silica, calcium carbonate, sodium carbonate | Low melting point, easy to shape. |
| Borosilicate glass | Silica, boron oxide, sodium oxide, aluminium oxide | High resistance to heat and chemicals compared to soda-lime glass. |
| Lead crystal glass | Silica, lead(II) oxide, sodium oxide | Low melting point, high refractive index. |
Properties of Ceramic
- Can withstand high temperature and high pressure.
- Very hard.
- Brittle.
- Chemically inert.
- Does not rust.
- Good insulator of heat and electricity.
Applications of Glass and Ceramic in Daily Life
The properties of each material determine how it is used.
Applications of Glass
Borosilicate glass is used for laboratory apparatus such as beakers and conical flasks because of its high resistance to heat and chemicals.
Soda-lime glass is used for light bulbs because of its resistance to heat and ease of shaping.
Lead crystal glass is used for glass prisms to study the dispersion of light because of its high refractive index.
Transparent glass is used for window panes to allow light to enter houses and buildings.
Applications of Ceramic
Tableware such as plates, bowls and cups is made of ceramic because of its resistance to heat and corrosion.
Dentures are made of ceramic due to its hardness and chemically inert nature.
Ceramic tiles are used for flooring because of their sparkling property that makes floors look clean and nice.
Flower pots are made of ceramic because they are hard and strong.
Try to Answer First
Answer in your mind, then press “Check Answer”.
What are the main chemical components in glass and ceramic?
Why are laboratory beakers and flasks made of borosilicate glass instead of soda-lime glass?
State two reasons why ceramic is used to make dentures.
Common Mistakes
- Confusing the composition of soda-lime glass with borosilicate glass by forgetting that borosilicate glass contains boron oxide and aluminium oxide.
- Thinking that ceramics conduct electricity because they are hard like metals; in fact, ceramics are good electrical and thermal insulators.
- Forgetting that lead crystal glass contains lead(II) oxide, which is responsible for giving it a high refractive index.
Concept Misunderstandings
All glass types withstand the same high temperatures.
Pure fused silica glass and borosilicate glass have high heat resistance, whereas soda-lime glass and lead crystal glass have relatively low melting points.
Clay and ceramic are the same material.
Clay is the raw material containing aluminium silicate, whereas ceramic is the finished product produced after subjecting clay to high-temperature heat reactions.
Summary
- Glass is made from silica (silicon dioxide). Pure silica melts at around 1500°C.
- Fused silica glass has high heat resistance and is chemically inert.
- Soda-lime glass has a low melting point and is easy to shape (used in bulbs).
- Borosilicate glass resists heat and chemicals (used in laboratory apparatus).
- Lead crystal glass has a high refractive index (used in prisms).
- Ceramic is formed from heating clay (aluminium silicate) at very high temperatures.
- Ceramics are hard, brittle, heat-resistant, chemically inert, rust-proof, and good insulators of heat and electricity.
Short Activity
A. Objective Quiz
1 Which type of glass is composed of silica, boron oxide, sodium oxide, and aluminium oxide, making it suitable for laboratory apparatus?
2 What is the main component in clay used to manufacture ceramics?
B. Fill in the Blanks
3 Lead crystal glass is used to make optical prisms because it has a high index.
4 Pure silica melts and liquefies at approximately °C to form glass.
C. Drag and Drop: Match the Material to Its Property or Purpose
Drag each material or product to its correct property or purpose. On a phone, tap an answer first, then tap a matching box. Tap the Answer Choices area to return a selected item.
C. Match the Material to Its Property or Purpose
Write the correct material or product next to each property or purpose.
| Property or Application | Material / Product |
|---|---|
| 1. High resistance to heat and chemicals for laboratory apparatus | |
| 2. Low melting point and easily shaped to make electric bulbs | |
| 3. High refractive index used to study the dispersion of light | |
| 4. Hard and chemically inert material used to make dentures |
Answer choices: Borosilicate glass • Soda-lime glass • Lead crystal glass • Ceramic
