Metals and Non-metals: Properties and Uses

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• Chemistry
• Lower Secondary (Key Stage 3)

Metals and Non-metals

This KS3 chemistry lesson explores Metals and Non-Metals: Properties and Uses. Students compare the physical and chemical properties of metals and non-metals and link those properties to everyday uses. It provides a clear introduction to the topic and can be used for classroom teaching, homework or revision.

Metals and Non Metals, KS3 Science, Chemistry, Periodic Table, Conductors, Insulators, Malleability, Ductility, Metal Oxides, Non Metal Oxides, Physical Properties, MCQs, Open Questions, Polls, Emoji Polls, Exit Tickets

What is the best word to describe what makes something a metal?

Use this to surface prior ideas such as shiny, dull, conductor, brittle, solid, gas, ions or reactions. Pick a few student words to revisit later and check whether they still fit after the lesson.

Two broad groups of elements

Elements are often grouped as metals or non-metals.

This classification is based on patterns in their physical properties and chemical behaviour.

At GCSE level, these patterns can also be linked to particle structure and bonding.

Avoid suggesting that every element fits perfectly into a simple rule; keep the focus on broad GCSE patterns.

Physical properties: main contrasts

Non-metals

Metals

• usually dull

• often low density

• brittle if solid

• not ductile

• poor conductors of heat

• poor conductors of electricity

• often lower melting points

• many are gases or brittle solids at room temperature

• usually shiny

• often high density

• malleable

• ductile

• good conductors of heat

• good conductors of electricity

• usually high melting points

• mostly solids at room temperature

Use 'usually' and 'often' carefully so students see these as trends, not absolute rules.

Typical metals

• Copper: reddish, excellent electrical conductor

• Iron: strong, dense, magnetic

• Aluminium: low density, malleable, useful for transport and packaging

These examples show that metals share core features, even though each metal has its own uses.

You may mention that magnetic behaviour is not a defining property of all metals; it is specific to a few, including iron.

Typical non-metals

• Carbon: a solid non-metal

• Sulfur: a yellow, brittle solid

• Chlorine: a pale green gas

These examples show that non-metals can exist in different states at room temperature.

Keep the emphasis on variation within the non-metals, especially state at room temperature.

Why metals have these properties

In a metal, atoms form a giant metallic lattice. The outer electrons are delocalised, meaning they can move through the structure.

Because layers of metal ions can slide past each other, metals are malleable and ductile. Because delocalised electrons can move, metals conduct electricity and heat well.

Students do not need a full bonding derivation here; focus on the link between metallic bonding and observable properties.

Why non-metals are different

Many non-metals have simple molecular structures with strong bonds inside each molecule but weaker forces between molecules.

This helps explain why many non-metals have low melting points and are gases or brittle solids. Non-metals also usually lack free-moving charged particles, so they are poor conductors of electricity.

Acknowledge that carbon is a useful reminder that non-metals are not all identical, but do not go beyond the basic pattern unless needed.

Which property is more typical of a metal?

A

Brittle

B

Ductile

C

Dull

D

Low density

Checks the physical-properties contrast from slides 3 to 5. Distractors are all typical non-metal trends students may confuse with metal properties.

Complete the summary

Metals usually have a giant metallic lattice with delocalised electrons that can move. This helps explain why metals conduct electricity well, while many non-metals are poor conductors and often have low melting points.

lattice

delocalised electrons

electricity

melting points

molecules

protons

insulator

density

negative ions

Echoes the wording from slides 6 and 7 and links structure to observable properties.

What happens when metals react

Metals tend to lose electrons when they react.

Losing electrons forms positive ions.

For example:

Mg → Mg²⁺ + 2e⁻

This is why metals often form ionic compounds with non-metals.

Connect this back to outer electrons in metals being easier to remove than in non-metals.

What happens when non-metals react

Non-metals tend to gain electrons when they react.

Gaining electrons forms negative ions.

For example:

Cl + e⁻ → Cl⁻

This helps explain why metals and non-metals often react together.

Make clear that chlorine exists as molecules in reality, but this simplified ion-forming example is standard for showing electron gain.

Oxides: a key chemical contrast

• formed when non-metals react with oxygen

• usually covalent substances

• examples include carbon dioxide and sulfur dioxide

• many are acidic

Metal oxides

Non-metal oxides

• formed when metals react with oxygen

• usually ionic compounds

• examples include magnesium oxide and iron oxide

• many are basic

Keep this at the level of broad trends. 'Basic' and 'acidic' can be linked to their behaviour in water if needed, but do not over-expand.

Why many metals are found in ores

Because metals tend to lose electrons, they are often reactive enough to combine with other elements.

Over time, this means many metals are found as compounds in rocks, called ores, rather than as pure elements.

Iron is commonly found in iron oxide ores.

This is a good place to contrast less reactive metals, which are sometimes found native, without making that the main lesson focus.

Why do metals and non-metals often react together?

Expected elements: metals lose electrons to form positive ions; non-metals gain electrons to form negative ions; this helps explain ionic compounds forming between them.

When magnesium reacts, what does it form?

A

A negative ion

B

A neutral atom

C

A positive ion

D

A covalent molecule

Based on slide 8: Mg loses electrons to form Mg2+. The distractors match common confusions about ions and bonding.

Complete the reactions summary

Metals tend to lose electrons and form positive ions. Non-metals tend to gain electrons and form negative ions. Many metals are found as compounds in ores rather than as pure elements.

lose electrons

positive ions

gain electrons

negative ions

ores

share electrons

neutral atoms

covalent bonds

molecules

alloys

Draws together slides 8 to 11, including ion formation and why metals are commonly found in ores.

Classifying an element

To classify an element, look at both its properties and its reactions.

• conducts electricity well → likely a metal

• brittle and dull → likely a non-metal

• forms positive ions → metal

• forms negative ions → non-metal

Stress that classification is stronger when several clues agree, rather than from one property alone.

Metals and non-metals: summary

Metals and non-metals differ in appearance, density, strength, conductivity, melting point, state, and reaction pattern.

These differences are not random. They come from differences in bonding, structure, and the way atoms gain or lose electrons.

That is why chemists can use evidence to classify elements into these two groups.

Use this slide to pull the lesson back to the central idea: observable properties reflect particle-level structure.

An element is dull, brittle and forms negative ions. It is likely a...

A

Metal

B

Non-metal

C

Mixture

D

Alloy

Applies the classification rules from slides 12 and 13. Mixture and alloy are plausible chemistry terms but not element groups.

Which clue is most useful when classifying an element?

1

Conductivity

2

State

3

Ion formed

4

Several clues together

How well do you understand what makes something metal now?

Glossary 1

metal - an element that usually conducts heat and electricity well and tends to form positive ions

non-metal - an element that usually conducts poorly and tends to form negative ions

malleable - able to be hammered or bent into shape

ductile - able to be drawn into wires

conductivity - how easily heat or electricity passes through a substance

positive ion - a charged particle formed when an atom loses electrons

negative ion - a charged particle formed when an atom gains electrons

Glossary 2

metallic bonding - bonding in metals caused by attraction between positive metal ions and delocalised electrons

delocalised electrons - electrons that are free to move through a metal structure

giant metallic lattice - a regular structure of positive metal ions in a sea of delocalised electrons

oxide - a compound containing oxygen and one other element

ore - a rock containing enough metal compound for extraction to be worthwhile

ionic compound - a compound made from oppositely charged ions

covalent - describing bonding where atoms share electrons