Science · Year 9 · Atomic Structure and Periodic Trends · Autumn Term

Metals and Non-metals

Students will compare the physical and chemical properties of metals and non-metals.

• National Curriculum Attainment Targets
• KS3: Science - The Periodic Table

About This Topic

Students compare the physical and chemical properties that define metals and non-metals within the periodic table. Metals show lustre, good electrical and thermal conductivity, malleability, ductility, high density, and sonority. Non-metals appear dull, conduct poorly, prove brittle, display low density, and lack resonance when struck. These traits stem from metallic bonding in metals, which allows delocalised electrons for conduction and shape change, versus covalent or ionic structures in non-metals.

Chemical properties highlight reactivity differences. Metals form positive ions by losing electrons and react with acids to produce hydrogen gas, with reactivity increasing down a group due to larger atomic radius and weaker nuclear attraction, but decreasing across a period as ionisation energy rises. Non-metals gain electrons to form negative ions and often react with metals. Students predict element types from property lists, applying trends from atomic structure.

Active learning suits this topic well. When students test real samples for conductivity or malleability in controlled stations, or observe metal-acid reactions in pairs, properties shift from abstract lists to concrete evidence. This approach fosters prediction skills and deepens periodic table understanding through trial and discussion.

Key Questions

1. Compare the characteristic physical properties of metals and non-metals.
2. Explain how the reactivity of metals changes across a period and down a group.
3. Predict whether an unknown element is a metal or non-metal based on its properties.

Learning Objectives

• Compare the physical properties of at least five common metals and five common non-metals, identifying at least three characteristic differences.
• Explain the relationship between metallic bonding and the observed physical properties of metals, such as conductivity and malleability.
• Classify an unknown element as a metal or non-metal based on a provided list of its physical and chemical properties.
• Analyze the trend in reactivity of alkali metals down Group 1 of the periodic table, explaining the underlying atomic structure reasons.
• Predict the likely products of reactions between metals and acids or non-metals and metals.

Before You Start

Atomic Structure

Why: Understanding the arrangement of electrons, protons, and neutrons in an atom is fundamental to explaining bonding and reactivity trends.

Elements and Compounds

Why: Students need to know what elements are and how they combine to form compounds to understand the nature of metallic and non-metallic substances.

Key Vocabulary

Lustre	The way light reflects off the surface of a substance. Metals typically have a shiny, lustrous appearance, while non-metals are often dull.
Malleability	The ability of a solid material to bend or be hammered into thin sheets without breaking. Metals are generally malleable, whereas non-metals are brittle.
Ductility	The ability of a solid material to be stretched into a wire. Metals exhibit ductility due to their bonding structure.
Sonority	The property of making a deep, ringing sound when struck. Metals are often sonorous, unlike most non-metals.
Reactivity Series	A list of metals arranged in order of their reactivity. This series helps predict how metals will react with other substances like acids or water.

Watch Out for These Misconceptions

Common Misconception

All metals are magnetic.

What to Teach Instead

Only iron, cobalt, nickel, and alloys like steel show magnetism; most metals like copper or aluminium do not. Hands-on magnet tests with samples let students classify accurately and discuss electron spin origins in pairs.

Common Misconception

Reactivity of metals increases across a period from left to right.

What to Teach Instead

Reactivity decreases across a period due to rising ionisation energy. Reactivity series demos with acids help students sequence metals by observation, correcting the trend through collaborative ranking.

Common Misconception

Non-metals never conduct electricity.

What to Teach Instead

Graphite conducts due to delocalised electrons, unlike diamond. Circuit tests on carbon allotropes reveal exceptions, prompting group discussions on structure-property links.

Active Learning Ideas

Stations Rotation: Physical Property Tests

Prepare stations for lustre (torch on samples), conductivity (simple circuits with bulbs), malleability (bend wires or hammer foil safely), and density (weigh equal volumes). Small groups spend 8 minutes per station, sketching observations and noting metal or non-metal traits. Conclude with class share-out.

45 min·Small Groups

Pairs: Metal Reactivity Series

Provide magnesium ribbon, zinc granules, and copper turnings with dilute hydrochloric acid in test tubes. Pairs add equal masses to acid, time hydrogen bubble rates, and rank reactivity. Discuss why magnesium reacts fastest, linking to group trends.

30 min·Pairs

Whole Class: Property Prediction Game

Display projected lists of properties (e.g., 'brittle, poor conductor'). Students hold up 'metal' or 'non-metal' cards, then justify in pairs. Reveal element identity and vote on correct predictions, addressing trends across periods.

20 min·Whole Class

Individual: Element Classification Chart

Students receive data cards with properties for 10 elements. They sort into metal/non-metal columns, predict positions in periodic table, and explain reactivity based on group/period. Share one challenging example with class.

25 min·Individual

Real-World Connections

• Metallurgists in the aerospace industry select specific metal alloys, considering properties like strength, low density, and resistance to corrosion, for constructing aircraft components.
• Electrical engineers use copper, a highly conductive metal, to manufacture wires and circuits for power transmission and electronic devices, while insulators like rubber or plastic, which are non-metals, protect these wires.
• Jewelers work with metals like gold and silver, valuing their malleability and lustre to shape them into intricate designs for jewelry, often alloying them with other metals to enhance durability.

Assessment Ideas

Quick Check

Present students with a table listing properties (e.g., shiny, brittle, conducts electricity, low melting point) for three unknown elements. Ask them to label each element as 'Metal' or 'Non-metal' and provide one property that led to their decision.

Discussion Prompt

Pose the question: 'Imagine you are designing a new type of cooking pot. What properties would you look for in the material, and would you choose a metal or a non-metal? Explain your reasoning using at least two specific properties.'

Exit Ticket

On a small card, ask students to write down one physical property that distinguishes most metals from most non-metals, and one chemical property that highlights a difference in their reactivity.

Frequently Asked Questions

How do physical properties of metals differ from non-metals?

Metals conduct electricity and heat, appear shiny, bend without breaking, and ring when hit. Non-metals insulate, look dull, shatter easily, and sound dead. These arise from metallic bonding versus covalent bonds. Testing samples confirms traits, aiding prediction of element types in the periodic table.

What causes reactivity trends in metals?

Down a group, larger atoms and shielding reduce nuclear pull, easing electron loss and boosting reactivity. Across a period, stronger nuclear charge holds electrons tighter, lowering reactivity. Acid reaction demos quantify this, helping students plot trends and predict behaviours for unknown metals.

How can active learning help students distinguish metals from non-metals?

Station rotations with conductivity circuits, bending tests, and acid reactions give direct evidence of properties. Students record data collaboratively, predict classifications, and debate results, turning rote lists into experiential knowledge. This builds confidence in applying periodic trends during predictions.

Why study metals and non-metals in Year 9?

This topic connects atomic structure to observable properties and reactivity, fulfilling KS3 periodic table standards. It equips students to explain everyday uses, like wiring or alloys, and prepares for GCSE reactions. Practical tests reinforce systems thinking across the curriculum.