Metal properties and reaction patterns
Compare physical behaviour separately from reactions with acids, water, steam and oxygen.
Cross-referenced from the related Cambridge IGCSE Chemistry 0620 or Physics 0625 teaching to the 0652 syllabus. Exact 0652 Core/Supplement objective coverage and this final-series course’s examiner fit still need specialist review. Written practice is self-checked and does not predict a Cambridge grade or demonstrate supervised laboratory competence.
Before you begin
- Connect metallic bonding with mobile electrons and deformation.
- Distinguish physical changes from formation of new substances.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which process necessarily forms a new substance in the stated examples?
What you will learn
- Compare general metal and non-metal thermal/electrical conductivity, shaping and melting/boiling behaviour.
- Describe suitable metal reactions with dilute acids, cold water, steam and oxygen under stated conditions.
Physical properties are different tests
Metals generally conduct electricity and heat well, can be hammered into shapes (malleable) and drawn into wires (ductile). Many have relatively high melting and boiling points. Most non-metals are poor electrical conductors and, when solid, often brittle rather than malleable or ductile. These are general comparisons: graphite conducts electricity, some giant covalent substances have very high melting points, and not every metal has a high melting point.
Do not combine the properties into one vague claim that metals are strong. Malleability concerns hammering or shaping, ductility drawing into wires, electrical conductivity charge movement and thermal conductivity energy transfer. Melting is a physical state change and need not form a new substance, whereas reaction with oxygen forms a different substance. Use supplied property data for a named comparison rather than overriding it with a general rule.
Chemical behaviour depends on the metal and conditions
Suitable metals above hydrogen react with dilute hydrochloric acid to produce chloride salt and hydrogen, such as Mg+2HCl→MgCl₂+H₂; copper does not give this hydrogen reaction under the stated dilute-HCl comparison. Reactive potassium, sodium and calcium react with cold water to give hydroxide and hydrogen. Magnesium reacts readily with steam to give magnesium oxide and hydrogen: Mg+H₂O(g)→MgO+H₂. Do not give the steam reaction the cold-water hydroxide product automatically.
Many metals react with oxygen to form oxides under suitable conditions; for magnesium, 2Mg+O₂→2MgO. A less reactive metal can need heating for an observable oxide formation, and very unreactive examples may not show the same simple reaction. The reactivity-series lessons organise the named comparisons. These equations explain supervised evidence; they are not directions to handle reactive metals, steam or burning samples at home.
Sources for this lesson
Pause and explain
Which products belong to magnesium with steam in the stated comparison?
Worked example
Compare magnesium melting with magnesium burning in oxygen, and state the product of magnesium with steam.
Show the worked solution
- Melting changes Mg's state while it remains magnesium, so it is physical.
- Burning forms MgO through 2Mg+O₂→2MgO, a chemical reaction.
- With steam, Mg+H₂O(g)→MgO+H₂ gives oxide and hydrogen rather than the same event as melting.
Answer Melting is physical; oxygen reaction gives MgO; steam gives MgO and H₂.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Compare a typical metal and solid non-metal for electrical conductivity, thermal conductivity and shaping, retaining the general-rule limits.
Give me a hint
Name each property rather than using one word for all of them.
Compare my reasoning
- Metals generally conduct electricity and heat well; most non-metals are poorer conductors.
- Metals are generally malleable and ductile; many solid non-metals are brittle.
- Use exceptions and supplied data, for example graphite's electrical conduction, rather than claiming every case is identical.
Typical metals conduct and can be shaped; many solid non-metals conduct poorly and are brittle, with exceptions.
Look for these in your work
- The three comparisons are separated.
- General rather than universal wording is used.
Write balanced equations for magnesium with dilute HCl, steam and oxygen, naming the other product when present.
Give me a hint
Keep the reactant identities and product patterns separate.
Compare my reasoning
- Mg+2HCl→MgCl₂+H₂ gives hydrogen.
- Mg+H₂O(g)→MgO+H₂ also gives hydrogen, with oxide rather than chloride.
- 2Mg+O₂→2MgO forms the oxide without hydrogen.
Mg+2HCl→MgCl₂+H₂; Mg+H₂O(g)→MgO+H₂; 2Mg+O₂→2MgO.
Look for these in your work
- All equations conserve atoms.
- Water, acid and oxygen patterns remain distinct.
A proposed classification labels a material non-metal solely because it has a low melting point, and labels all gas-producing acid reactions metal reactions. Evaluate both shortcuts.
Give me a hint
Physical generalisations and reaction observations need substance identity and conditions.
Compare my reasoning
- Metals have varied melting points, so low melting point alone does not establish a non-metal.
- An acid with a carbonate can produce CO₂, while a suitable metal with dilute HCl produces H₂.
- Use several relevant properties or the actual reactants and gas identity, rather than either shortcut.
Neither shortcut is sufficient; use property evidence and identify reactants and products.
Look for these in your work
- Both overgeneralised rules are corrected.
- Concrete alternative explanations are supplied.
Common mistakes
- Confusing malleability with electrical conductivity.
- Claiming every non-metal is an electrical insulator.
- Predicting hydrogen from copper and dilute HCl.
- Using magnesium hydroxide as the stated steam product.
What can you explain now?
What do malleable and ductile mean respectively?
Compare with the explanation
Can be hammered into shapes; can be drawn into wires.
Both describe shaping properties, but they refer to different forms of deformation.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Recall each physical comparison separately. Write three suitable metal equations and distinguish their products from a physical state change.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.