Properties of Metals

Property questions look like free marks, and that is the trap: 0620 mark schemes reject “metals are strong” and “metals are hard” because neither is a defining property. The scoring vocabulary is short (conductor, malleable, ductile, basic oxide, positive ion), and this page pins down each word, as the foundation for the rest of the Metals topic.

Physical properties: the vocabulary that scores

Property	Metals	Non-metals (solid)
Electrical conduction	Good conductors	Poor conductors (insulators), except graphite
Heat conduction	Good conductors	Poor conductors
Shaping	Malleable and ductile	Brittle: shatter when hit
Melting/boiling point	Usually high	Usually low
Density	Usually high	Usually low
Appearance	Shiny (lustrous) when polished	Dull

Two definitions are tested by name: malleable means the metal can be hammered or bent into shape without shattering; ductile means it can be drawn out into wires. Use the technical word and then, if the question asks, define it. “Metals can be bent” without “malleable” can score, but the reverse question (“what does malleable mean?”) is common.

Exceptions are worth a line in your notes because Cambridge uses them to test whether you understand that these are patterns, not laws. The Group I metals are soft, low-density (lithium, sodium and potassium float on water) and melt below 100 °C in sodium’s case. Graphite is the non-metal exception: it conducts electricity. Diamond, a non-metal, has an extremely high melting point.

Chemical properties: ions and oxides

Two chemical contrasts define metals at 0620:

1. Metals form positive ions. In reactions, metal atoms lose electrons: Na → Na+ + e−, Mg → Mg2+ + 2e−. Non-metals gain or share electrons, forming negative ions in ionic compounds.
2. Metal oxides are basic; non-metal oxides are acidic. Magnesium oxide neutralises acids; sulfur dioxide and carbon dioxide turn damp litmus red. (Aluminium oxide is amphoteric, meaning it reacts with both acids and bases, a detail that appears on Extended papers via acids, bases and salts.)

The classification question follows directly: given an unknown element that conducts electricity, is malleable, and forms a basic oxide, you classify it as a metal and justify each property. Given a brittle solid whose oxide dissolves to give pH 3, you have a non-metal.

Linking properties to uses

Use-and-property questions are marked on the link, not the fact:

• Copper for electrical wiring: excellent conductor of electricity and ductile (drawn into wire)
• Aluminium for aircraft and drink cans: low density (and resists corrosion due to its oxide layer)
• Iron/steel for bridges and construction: strong and cheap, usually as an alloy (alloys page)

Each line needs the property and the reason it suits the job. “Copper is used in wires because it is a metal” scores zero.

Why metals behave this way (Supplement link)

The Extended explanation lives in metallic bonding: a lattice of positive ions in a “sea” of delocalised electrons. The mobile electrons explain electrical and thermal conduction; the layers of ions sliding over each other explain malleability. At Core you state the properties; at Supplement you can be asked to explain them with this model, covered fully under metallic bonding.

Worked exam question

Element Z is a shiny solid that conducts electricity. Its oxide dissolves in water to give a solution of pH 13. (a) State, with two reasons, whether Z is a metal or a non-metal. [3] (b) Z can be hammered into thin sheets. Give the word that describes this property. [1]

Model answer: (a) Z is a metal (1); it conducts electricity (1); its oxide is basic / gives an alkaline solution of pH 13 (1). (b) Malleable (1).

Mark-by-mark: (a) the classification alone earns one mark only if backed by evidence from the question; the conduction mark and the basic-oxide mark must reference the data given. “It is shiny” is weaker evidence but accepted; pH 13 means alkaline, which only a metal oxide produces. (b) is one exact word; “bendable” or “flexible” is not on the scheme.

The mistakes that cost marks

1. “Strong” and “hard” as properties. Neither is on 0620 mark schemes as a defining metal property. Use conductor, malleable, ductile, high melting point, high density.
2. Mixing up malleable and ductile. Malleable = hammered into sheets; ductile = drawn into wires. Swapped definitions lose the mark even when both words appear.
3. Forgetting the oxide rule’s direction. Metal oxide → basic; non-metal oxide → acidic. Reversing it wrecks classification questions, and it feeds into pH evidence too.
4. Use-questions without the property link. Every “why is X used for Y” answer needs the property named and connected to the job.

How examiners want it phrased

Student wording	Mark-scheme wording
”Metals are strong and tough"	"Metals are malleable, ductile and good conductors of heat and electricity"
"It’s a metal because it looks like one"	"It conducts electricity and forms a basic oxide, so it is a metal"
"Copper is good for wires"	"Copper is used for wiring because it is an excellent electrical conductor and is ductile"
"Metals make alkalis"	"Metal oxides are basic; soluble ones form alkaline solutions”

Once the vocabulary is automatic, this subtopic funds easy marks before the harder material in the reactivity series begins. If your answers keep saying “strong” where the scheme says “malleable”, one free trial lesson of mark-scheme drilling will fix it.

Test yourself

Use the scoring vocabulary (conductor, malleable, ductile, basic), then check below.

Q1 (2 marks). Define the terms malleable and ductile.

Show answer

• malleable: can be hammered or bent into shape without shattering [1] • ductile: can be drawn out into wires [1]

Q2 (2 marks). Aluminium is used to build aircraft. Give two properties of aluminium that make it suitable, linking each to the use.

Show answer

• low density, so the aircraft is lighter / uses less fuel [1] • resists corrosion, because its surface oxide layer protects the metal beneath [1]

Q3 (2 marks). Element Q is a brittle solid that does not conduct electricity. Its oxide dissolves in water to give a solution of pH 2. State, with two reasons from the data, whether Q is a metal or a non-metal.

Show answer

• Q is a non-metal: it is brittle and a poor electrical conductor [1] • its oxide is acidic (pH 2), and non-metal oxides are acidic [1]