The World of Metals and Non-metals
Discover how metals and non-metals differ in their physical and chemical properties, how they react, why metals corrode, and how their properties determine their everyday uses.
Chapter Snapshot
- Elements can broadly show metallic or non-metallic properties.
- Metals are generally lustrous, hard, malleable, ductile, sonorous and good conductors.
- Non-metals generally show properties different from metals and solid non-metals are often brittle.
- Physical properties help us choose suitable materials for different purposes.
- Metals and non-metals can react differently with oxygen.
- Metal oxides are generally basic, while many non-metal oxides are acidic.
- Iron can slowly react with air and moisture to form rust.
- A more reactive metal can replace a less reactive metal from some of its compounds.
- Metals and non-metals have many important uses in homes, agriculture, construction, technology and industry.
What You Will Learn
- Identify common metals and non-metals found in everyday life
- Describe the major physical properties of metals
- Describe the major physical properties of non-metals
- Explain malleability, ductility, sonority and conductivity
- Compare metals and non-metals using observable properties
- Explain how metals and non-metals react with oxygen
- Describe rusting and the conditions required for rust formation
- Explain common methods used to prevent rusting
- Understand the basic idea of a displacement reaction
- Relate the properties of metals and non-metals to their everyday uses
Chapter Overview
Look around you. A steel spoon, aluminium foil, copper electrical wire, iron gate, gold ornament, graphite pencil core, oxygen in the air and sulphur used in chemical processes may seem very different from one another.
Yet many of these substances can be understood by studying two broad groups of elements — metals and non-metals.
The properties of a material determine where it can be used. Copper is useful for electrical wiring because it conducts electricity and can be drawn into wires. Aluminium is useful for making thin foil because it can be beaten into sheets. Iron is used in tools and structures because it is strong, although it needs protection from rust.
Understanding materials therefore means asking not only “What is this substance?” but also “What properties does it have, and how do those properties make it useful?”
Detailed Explanation
1. Elements, Metals and Non-metals
Matter around us is made from different substances. Some substances are elements.
Examples include:
- iron;
- copper;
- aluminium;
- gold;
- oxygen;
- carbon;
- sulphur.
Many elements are classified as either metals or non-metals according to their characteristic physical and chemical properties.
Examples include:
- iron;
- copper;
- aluminium;
- gold;
- silver;
- zinc.
Examples include:
- oxygen;
- sulphur;
- carbon;
- phosphorus;
- nitrogen.
2. Physical Properties of Metals
Physical properties are characteristics that can be observed or measured without changing a substance into a different substance.
Let us examine the common physical properties of metals.
2.1 Metallic Lustre
Freshly cut or polished metals generally have a characteristic shine.
Gold, silver, copper and polished aluminium show metallic lustre.
However, a metal surface may become dull after exposure to air because a layer of another substance forms on its surface.
An old iron object may look dull.
If a fresh metal surface is exposed by suitable polishing, the newly exposed surface can appear much shinier.
This shows that surface appearance may change due to substances formed on the outer layer.
2.2 Hardness
Many metals are hard and strong.
Iron, for example, is useful in tools, gates, machinery and construction because of its strength.
However, properties of metals are general tendencies, not rules without exceptions.
Do not memorise:
“All metals are hard.”
A better scientific statement is:
“Most familiar metals are hard, but there are exceptions.”
Science classifications are based on several properties together rather than a single observation.
2.3 Malleability
Why can aluminium be converted into extremely thin foil?
The answer lies in a property called malleability.
Metals such as aluminium, gold and silver can be formed into thin sheets.
This property has many practical applications.
Aluminium can be rolled into very thin sheets.
This makes aluminium useful for applications such as wrapping and packaging.
Its use is directly connected with its malleability.
2.4 Ductility
Electrical wires are often extremely thin compared with the original piece of metal from which they were made.
Copper and aluminium are useful for making wires partly because they are ductile.
Show answer
2.5 Sonority
When some metal objects are struck, they produce a clear ringing sound.
Materials that show this property are described as sonorous.
This is one reason metals have traditionally been used in bells and certain musical instruments.
2.6 Conductivity
Metals are usually good conductors of heat and electricity.
Copper and aluminium are widely used as conducting materials in electrical applications.
This directly connects Chapter 4 with your study of electric circuits.
Metal cooking utensils transfer heat efficiently from the heat source to food.
3. Investigating Physical Properties of Metals
4. Physical Properties of Non-metals
Non-metals generally show physical properties different from metals.
4.1 Appearance
Many solid non-metals are dull rather than metallic and shiny.
Sulphur, for example, does not normally show metallic lustre.
However, just as with metals, exceptions exist.
4.2 Brittleness
Solid non-metals generally cannot be hammered into thin sheets.
Instead, they may break.
Solid non-metals such as sulphur are brittle.
Therefore, non-metals are generally:
- not malleable;
- not ductile.
4.3 Sonority
Non-metals are generally non-sonorous.
They do not usually produce the characteristic metallic ringing sound when struck.
4.4 Conductivity
Most non-metals are poor conductors of electricity.
However, this also has an important exception.
4.5 Physical State
Non-metals occur in different physical states at ordinary temperatures.
Examples include:
- oxygen — gas;
- nitrogen — gas;
- sulphur — solid;
- carbon — solid.
Thus, unlike the common idea that every element must be a solid, many important non-metals are gases.
General Physical Properties of Metals and Non-metals
| Property | Metals | Non-metals |
|---|---|---|
| Lustre | Generally lustrous | Generally dull |
| Malleability | Generally malleable | Generally not malleable |
| Ductility | Generally ductile | Generally not ductile |
| Sonority | Generally sonorous | Generally non-sonorous |
| Electrical conductivity | Generally good conductors | Generally poor conductors |
| Thermal conductivity | Generally good conductors | Generally poor conductors |
| Behaviour of solids under force | Many can be shaped | Solid non-metals are commonly brittle |
Show answer
5. Why Physical Properties Matter
Properties are not merely facts to memorise. They explain why different substances are used for different purposes.
Copper in electrical wires
Copper is useful because it is:
- a good electrical conductor;
- ductile;
- suitable for forming wires.
Aluminium in utensils and foil
Aluminium can be used because it is:
- a good conductor of heat;
- malleable;
- relatively lightweight compared with many familiar metals.
Iron in structures and tools
Iron is widely used because it is:
- strong;
- hard;
- useful for making many structural objects and tools.
However, iron has an important disadvantage — it can rust.
Gold and silver in ornaments
Gold and silver are valued partly because they:
- have attractive lustre;
- can be shaped;
- can be made into intricate forms.
When asked for the use of a material, connect the use with a property.
For example:
Copper is used in electrical wires because it conducts electricity well and can be drawn into wires.
This is better than simply writing:
Copper is used in wires.
6. Chemical Properties
Physical properties can be observed without producing a new substance.
Chemical behaviour is different.
In this chapter, important chemical behaviour includes:
- reactions with oxygen;
- formation of oxides;
- corrosion and rusting;
- displacement reactions.
7. Reaction of Metals with Oxygen
Many metals react with oxygen.
One useful example is magnesium.
When magnesium burns in oxygen, a white substance called magnesium oxide is formed.
Magnesium Reacts with Oxygen
[ 2Mg + O_2 \rightarrow 2MgO ]
where:
- (Mg) represents magnesium;
- (O_2) represents oxygen;
- (MgO) represents magnesium oxide.
This reaction forms a new substance, magnesium oxide.
Nature of metal oxides
Many metal oxides show a basic nature.
This connects the chapter with your earlier study of acids, bases and indicators.
For example, magnesium oxide can form magnesium hydroxide in the presence of water, and the resulting substance shows basic character.
8. Reaction of Non-metals with Oxygen
Non-metals can also react with oxygen.
The oxides formed by many non-metals show acidic behaviour.
A simple example can be represented using carbon.
Carbon Reacts with Oxygen
[ C + O_2 \rightarrow CO_2 ]
where:
- (C) represents carbon;
- (O_2) represents oxygen;
- (CO_2) represents carbon dioxide.
Carbon dioxide is a non-metal oxide.
Metals and Non-metals Reacting with Oxygen
| Feature | Metals | Non-metals |
|---|---|---|
| Reaction with oxygen | Form metal oxides | Form non-metal oxides |
| General nature of many oxides | Basic | Acidic |
| Example | Magnesium oxide | Carbon dioxide |
Show answer
9. Iron and Sulphur — Properties Can Change After a Chemical Reaction
Iron is a metal, while sulphur is a non-metal.
Before reaction:
- iron shows metallic properties;
- sulphur shows non-metallic properties.
When iron and sulphur react under suitable controlled conditions, a new compound called iron sulphide is formed.
Formation of Iron Sulphide
[ Fe + S \rightarrow FeS ]
where:
- (Fe) = iron;
- (S) = sulphur;
- (FeS) = iron sulphide.
The compound formed has properties different from those of the original iron and sulphur.
10. Corrosion
Have you seen an old metal object whose surface has changed after remaining outdoors for a long time?
Metals may slowly react with substances in their surroundings.
Examples of surface changes include:
- rust formation on iron;
- darkening or tarnishing of some metal surfaces;
- formation of coloured surface layers on some metals.
Corrosion can:
- damage metal objects;
- weaken structures;
- reduce the life of tools and machines;
- increase repair and replacement costs.
11. Rusting of Iron
Rusting is one of the most familiar examples of corrosion.
Iron objects such as:
- gates;
- railings;
- nails;
- tools;
- bicycle chains;
- outdoor machinery
can develop rust if they remain exposed to air and moisture.
Conditions required for rusting
Rusting needs:
- oxygen from air;
- water or moisture.
Removing access to either can greatly reduce rusting.
12. Preventing Rusting
If air and moisture are needed for rusting, we can protect iron by reducing their contact with the iron surface.
Common methods include:
Painting
Paint forms a protective layer between iron and its surroundings.
Used for:
- gates;
- railings;
- bridges;
- metal furniture.
Oiling
A thin oil layer helps protect some moving metal parts.
Used for:
- tools;
- machine parts;
- bicycle components.
Greasing
Grease can form a protective coating on suitable metal surfaces.
Galvanisation
NCERT identifies painting, oiling, greasing and applying a protective zinc layer as important ways of preventing rusting. ([NCERT][1])
Show answer
13. Displacement Reactions
Metals do not all react with other substances equally.
Some metals are more reactive than others.
A more reactive metal can sometimes replace a less reactive metal from a compound.
A commonly studied example involves iron and copper sulphate.
When an iron nail is placed in copper sulphate solution under suitable laboratory conditions, changes can be observed because iron can displace copper.
Iron and Copper Sulphate
[ Fe + CuSO_4 \rightarrow FeSO_4 + Cu ]
where:
- (Fe) = iron;
- (CuSO_4) = copper sulphate;
- (FeSO_4) = iron sulphate;
- (Cu) = copper.
The important idea is:
Iron is able to replace copper from copper sulphate.
This tells us that iron is more reactive than copper in this comparison.
If asked what a displacement reaction demonstrates, explain that it can help compare the relative reactivity of metals.
Show answer
14. Uses of Metals
Metals are used according to their properties.
Iron
Used in:
- tools;
- machinery;
- gates;
- building structures;
- transport equipment.
Useful properties include strength and hardness.
Copper
Used in:
- electrical wires;
- electrical equipment;
- some utensils and industrial applications.
Its good electrical conductivity and ductility are especially useful.
Aluminium
Used in:
- foil;
- utensils;
- containers;
- electrical applications;
- many lightweight structures.
It is useful because it is malleable, conductive and relatively lightweight.
Gold and Silver
Used in:
- jewellery;
- decorative objects;
- specialised applications.
Their lustre and ability to be shaped make them valuable for intricate objects.
Zinc
Zinc is used as a protective coating on iron during galvanisation.
Properties and Uses of Common Metals
| Metal | Useful Property | Example Use |
|---|---|---|
| Copper | Good conductor and ductile | Electrical wires |
| Aluminium | Malleable and good conductor | Foil and utensils |
| Iron | Strong and hard | Tools and structures |
| Gold | Lustrous and highly workable | Jewellery |
| Zinc | Can form a protective coating on iron | Galvanisation |
15. Uses of Non-metals
Non-metals are equally important.
Oxygen
Oxygen is essential for respiration in most familiar organisms and supports many processes involving combustion.
Nitrogen
Nitrogen is an important element in plant nutrition and is used in the production of many fertilisers.
Carbon
Carbon occurs in several forms and is an essential element in living organisms.
Graphite, a form of carbon, is used in applications where its special properties are useful.
Sulphur
Sulphur is used in various chemical and industrial processes.
Phosphorus
Phosphorus compounds are important in several biological and agricultural contexts.
The word non-metal only means that these elements do not show the typical collection of metallic properties.
It does not mean that non-metals are unimportant.
Oxygen, nitrogen, carbon, phosphorus and sulphur are all enormously important in nature and human life.
Connecting Physical and Chemical Properties
A good science student does more than memorise separate lists.
Consider the following chain of reasoning:
Property → Behaviour → Use or consequence
For example:
- Copper conducts electricity → current can pass through it easily → useful for wires.
- Aluminium is malleable → can form thin sheets → useful for foil.
- Iron reacts with oxygen and moisture → rust can form → protection is needed.
- A more reactive metal can displace a less reactive one → displacement reactions can compare reactivity.
Concept Map
Foundation Extension
Exam Focus
Important Exam Areas
- definitions of metal and non-metal;
- physical properties of metals;
- physical properties of non-metals;
- meaning of lustre;
- malleability and ductility;
- sonority;
- electrical and thermal conductivity;
- exceptions to general physical properties;
- differences between metals and non-metals;
- relationship between properties and uses;
- reaction of metals with oxygen;
- general nature of metal and non-metal oxides;
- rusting and conditions necessary for rusting;
- corrosion;
- methods of preventing rusting;
- galvanisation;
- displacement reaction;
- iron and copper sulphate reaction;
- uses of common metals and non-metals.
Key Terms
Key Terms
Chemical Equation Revision
Formula / Key Relations
Magnesium and Oxygen
[ 2Mg + O_2 \rightarrow 2MgO ]
Magnesium reacts with oxygen to form magnesium oxide.
Carbon and Oxygen
[ C + O_2 \rightarrow CO_2 ]
Carbon reacts with oxygen to form carbon dioxide.
Iron and Sulphur
[ Fe + S \rightarrow FeS ]
Iron and sulphur chemically combine to form iron sulphide.
Iron and Copper Sulphate
[ Fe + CuSO_4 \rightarrow FeSO_4 + Cu ]
Iron displaces copper from copper sulphate.
Quick Revision
Quick Revision
- Metal: An element that generally shows characteristic metallic properties.
- Non-metal: An element that generally lacks the usual combination of metallic properties.
- Lustre: Shiny appearance of a surface.
- Malleability: Ability to be beaten or rolled into sheets.
- Ductility: Ability to be drawn into wires.
- Sonority: Ability to produce a ringing sound when struck.
- Conductivity: Ability to allow heat or electric current to pass.
- Metals are generally good conductors of heat and electricity.
- Solid non-metals are generally brittle and are not malleable or ductile.
- Graphite is an important non-metallic conductor of electricity.
- Physical properties help determine how materials are used.
- Metals react with oxygen to form metal oxides.
- Many metal oxides show basic behaviour.
- Many non-metal oxides show acidic behaviour.
- Corrosion is the gradual deterioration of metals due to reactions with their surroundings.
- Rusting requires iron, oxygen and moisture.
- Painting, oiling, greasing and galvanisation can help prevent rusting.
- Galvanisation protects iron by coating it with zinc.
- A more reactive metal can displace a less reactive metal from certain compounds.
- Iron can displace copper from copper sulphate solution.
- Properties, reactions and uses of materials are closely connected.
Practice Questions
A. Multiple Choice Questions
Which property allows aluminium to be converted into thin foil?
A. Sonority B. Malleability C. Brittleness D. Acidity
View Solution
Correct Answer: B. Malleability
Malleability is the ability of a material to be beaten or rolled into thin sheets.
Which property allows copper to be made into thin electrical wires?
A. Ductility B. Brittleness C. Sonority D. Corrosion
View Solution
Correct Answer: A. Ductility
Ductility allows metals to be drawn into wires.
Which of the following is a non-metal?
A. Iron B. Aluminium C. Sulphur D. Copper
View Solution
Correct Answer: C. Sulphur
Sulphur is classified as a non-metal.
Which statement is generally correct?
A. Metals are poor conductors of electricity. B. Metals are generally malleable. C. Non-metals are generally ductile. D. Non-metals are generally sonorous.
View Solution
Correct Answer: B. Metals are generally malleable.
Most familiar metals can be beaten or rolled into sheets.
Which two conditions are especially important for rusting of iron?
A. Light and darkness B. Heat and sound C. Oxygen and moisture D. Plastic and glass
View Solution
Correct Answer: C. Oxygen and moisture
Rusting occurs when iron is exposed to suitable conditions involving both oxygen and water or moisture.
Which method protects iron by applying a zinc coating?
A. Distillation B. Galvanisation C. Filtration D. Crystallisation
View Solution
Correct Answer: B. Galvanisation
Galvanisation involves applying a protective zinc layer to iron or steel.
Iron can displace copper from copper sulphate solution. This indicates that:
A. copper is more reactive than iron B. iron is more reactive than copper C. iron is a non-metal D. copper is an insulator
View Solution
Correct Answer: B. iron is more reactive than copper
A more reactive metal can displace a less reactive metal from its compound.
Which of the following is an exception to the general statement that non-metals are poor electrical conductors?
A. Sulphur B. Oxygen C. Graphite D. Phosphorus
View Solution
Correct Answer: C. Graphite
Graphite is a form of carbon and can conduct electricity.
B. Very Short Answer Questions
-
What is lustre?
-
Define malleability.
-
Define ductility.
-
What is sonority?
-
Give two examples of metals.
-
Give two examples of non-metals.
-
What is corrosion?
-
What is rusting?
-
What is galvanisation?
-
What is a displacement reaction?
Answers
-
Lustre is the property by which a surface appears shiny because it reflects light.
-
Malleability is the ability of a material to be beaten or rolled into thin sheets.
-
Ductility is the ability of a material to be drawn into wires.
-
Sonority is the ability of a material to produce a ringing sound when struck.
-
Iron and copper.
-
Sulphur and oxygen.
-
Corrosion is the gradual deterioration of a metal due to reactions with substances in its surroundings.
-
Rusting is the formation of reddish-brown rust on iron under conditions involving oxygen and moisture.
-
Galvanisation is the application of a protective zinc coating to iron or steel.
-
A displacement reaction is a reaction in which a more reactive element replaces a less reactive element from its compound.
C. Short Answer Questions
Differentiate between malleability and ductility with one example of each.
View Solution
Malleability is the ability of a material to be beaten or rolled into thin sheets.
Example: aluminium can be made into foil.
Ductility is the ability of a material to be drawn into thin wires.
Example: copper can be drawn into electrical wires.
Why is copper suitable for making electrical wires?
View Solution
Copper is suitable for electrical wires because:
- it is a good conductor of electricity;
- it is ductile and can therefore be drawn into thin wires.
Thus, its physical properties match the requirements of electrical wiring.
Why is aluminium suitable for making foil?
View Solution
Aluminium is malleable, which means it can be rolled into very thin sheets without breaking.
This makes it suitable for manufacturing aluminium foil.
Why should the statement "all metals are hard and all non-metals are poor conductors" be avoided?
View Solution
The properties of metals and non-metals are general patterns and have exceptions.
For example, not every metal has exactly the same hardness, and graphite, which is a form of the non-metal carbon, can conduct electricity.
Therefore, scientific statements should normally use words such as generally or most.
Explain why painting an iron gate helps prevent rusting.
View Solution
Rusting requires contact between iron, oxygen and moisture.
Paint forms a protective layer over the iron surface. This reduces direct contact of iron with air and moisture and therefore helps prevent or slow rusting.
What happens when iron is placed in copper sulphate solution? What does the reaction tell us?
View Solution
Iron can displace copper from copper sulphate.
The reaction can be represented as:
[ Fe + CuSO_4 \rightarrow FeSO_4 + Cu ]
This shows that iron is more reactive than copper.
D. Long Answer Questions
Compare the physical properties of metals and non-metals.
View Solution
Metals and non-metals generally show contrasting physical properties.
Metals
Metals are generally:
- lustrous;
- malleable;
- ductile;
- sonorous;
- good conductors of heat;
- good conductors of electricity.
Non-metals
Non-metals are generally:
- dull;
- not malleable;
- not ductile;
- non-sonorous;
- poor conductors of heat;
- poor conductors of electricity.
Solid non-metals are often brittle.
However, these are general properties and exceptions exist. Therefore, several properties should be considered when classifying substances.
Explain rusting and describe four methods that can be used to protect iron from rusting.
View Solution
Rusting is a type of corrosion in which iron gradually develops a reddish-brown substance called rust when exposed to suitable conditions involving oxygen and moisture.
Iron can be protected by preventing or reducing contact with air and moisture.
Methods
-
Painting Paint creates a protective barrier.
-
Oiling Oil covers the metal surface and reduces contact with moisture and air.
-
Greasing Grease forms a protective coating on suitable machine parts.
-
Galvanisation Iron or steel is coated with zinc to provide protection.
All these methods reduce direct contact between iron and the surrounding environment.
Explain how the physical properties of metals determine their uses. Give at least four examples.
View Solution
The use of a metal is strongly related to its physical properties.
-
Copper — electrical wires Copper conducts electricity well and is ductile.
-
Aluminium — foil Aluminium is malleable and can be made into thin sheets.
-
Metals — cooking utensils Many metals conduct heat well, making them useful for cookware.
-
Iron — tools and structures Iron is strong and hard, making it useful in tools, gates and structures.
-
Gold and silver — jewellery Their lustre and ability to be shaped make them suitable for ornaments.
Thus, material selection is based on matching properties to purpose.
Application and HOTS Questions
A student says, "This object is shiny, so it must be a metal." Explain why this conclusion is scientifically weak.
View Solution
Shininess alone is not enough to classify an unknown substance.
Scientists should consider several properties, such as:
- conductivity;
- malleability;
- ductility;
- sonority;
- hardness;
- chemical behaviour.
Some non-metallic materials can also appear shiny under certain conditions.
Therefore, classification should be based on multiple observations, not just one property.
Two identical iron nails are kept in different conditions. Nail A remains dry, while Nail B is frequently exposed to moist air. Which nail is more likely to rust faster? Explain.
View Solution
Nail B is more likely to rust faster.
Rusting requires iron to come into contact with both oxygen and moisture.
Nail B is frequently exposed to moist air, providing favourable conditions for rusting.
The dry nail has much less access to moisture, so rust formation should be reduced.
A metal is a good conductor of electricity but breaks instead of forming a sheet when hammered. Should you classify it only from these two observations? Explain.
View Solution
No.
A reliable classification should consider several physical and, where appropriate, chemical properties.
Conductivity suggests metallic behaviour, while brittleness does not match the usual behaviour of many metals.
More evidence is therefore required before making a confident classification.
This illustrates why scientific conclusions should be based on multiple observations.
Why does a scratch in the paint on an iron gate increase the chance of rust developing at that point?
View Solution
Paint protects iron by forming a barrier between the metal surface and air and moisture.
A scratch exposes the underlying iron.
The exposed iron can then come into direct contact with oxygen and moisture, creating suitable conditions for rust formation.
Iron can displace copper from copper sulphate. Would it be scientifically correct to say that every metal can displace every other metal from its compounds?
View Solution
No.
Displacement depends on relative reactivity.
A metal can displace another metal only when the first metal is more reactive under the relevant conditions.
Therefore, the ability to displace another metal is not the same for every pair of metals.
Assertion–Reason
Assertion: Copper is widely used for electrical wiring.
Reason: Copper is a good conductor of electricity and is ductile.
Choose the correct option:
A. Both Assertion and Reason are true, and Reason correctly explains Assertion. B. Both are true, but Reason does not explain Assertion. C. Assertion is true, but Reason is false. D. Assertion is false, but Reason is true.
View Solution
Correct Answer: A
Copper's electrical conductivity allows current to pass through it, while its ductility allows it to be drawn into wires.
Both properties make copper suitable for electrical wiring.
Assertion: Painting an iron object can help prevent rusting.
Reason: Paint reduces direct contact of iron with air and moisture.
Choose the correct option:
A. Both Assertion and Reason are true, and Reason correctly explains Assertion. B. Both are true, but Reason does not explain Assertion. C. Assertion is true, but Reason is false. D. Both Assertion and Reason are false.
View Solution
Correct Answer: A
Rusting requires suitable exposure to oxygen and moisture. Paint forms a barrier that reduces this contact.
Apply Your Learning
Choose five safe objects around your home or classroom, for example:
- metal spoon;
- aluminium container;
- electrical wire;
- iron gate;
- jewellery item.
For each object, create a table with these headings:
| Object | Material | Important Property | Why That Property Is Useful | | ------------- | -------- | -------------------------- | ------------------------------------------ | | Example: Wire | Copper | Conductivity and ductility | Carries current and can be drawn into wire |
Then answer:
- Which object depends mainly on conductivity?
- Which object demonstrates malleability?
- Which metal object may need protection from corrosion?
- Which object contains both a conductor and an insulating material?
- Can you identify an object whose use depends on more than one material property?
Common Mistakes to Avoid
Final Chapter Summary
Chapter Summary
- Elements can show metallic or non-metallic properties.
- Metals are generally lustrous, malleable, ductile, sonorous and good conductors of heat and electricity.
- Non-metals generally lack these metallic properties, and solid non-metals are commonly brittle.
- Malleability means forming sheets, while ductility means forming wires.
- Physical properties explain why particular materials are selected for particular uses.
- Metals react with oxygen to form metal oxides, many of which show basic behaviour.
- Non-metals react with oxygen to form non-metal oxides, many of which show acidic behaviour.
- Chemical reactions produce new substances with properties different from the original substances.
- Corrosion is the gradual deterioration of metals through reactions with their surroundings.
- Rusting is a type of corrosion affecting iron and requires suitable exposure to oxygen and moisture.
- Painting, oiling, greasing and galvanisation are methods used to reduce rusting.
- Galvanisation protects iron or steel using a zinc coating.
- In a displacement reaction, a more reactive element replaces a less reactive element from its compound.
- Iron can displace copper from copper sulphate, showing that iron is more reactive than copper.
- Metals and non-metals are both essential in daily life, industry, agriculture, technology and living systems.