Properties of metals and non-metalsIB MYP Sciences: Revision notes
Section 1
Physical properties
Metals are usually:
- good conductors of heat and electricity
- malleable (can be hammered into sheets) and ductile (can be drawn into wires)
- shiny (lustre) when cut or polished, with high density and high melting points
Non-metals are usually poor conductors, brittle when solid, dull, and have lower densities and melting points. Some exceptions: mercury is a liquid metal, and graphite is a non-metal that conducts electricity.
Section 2
Chemical properties: oxides and acids
Metals react with oxygen to form metal oxides, which are basic. Non-metals react with oxygen to form non-metal oxides, which are usually acidic.
- magnesium + oxygen → magnesium oxide (2Mg + O₂ → 2MgO)
- sulfur + oxygen → sulfur dioxide (acidic)
Many metals react with dilute acid to form a salt and hydrogen:
- Mg + 2HCl → MgCl₂ + H₂
The hydrogen pops with a lit splint.
Section 3
The reactivity series
The reactivity series lists metals from most to least reactive:
potassium, sodium, lithium, calcium, magnesium, aluminium, (carbon), zinc, iron, (hydrogen), copper, silver, gold
A metal's position tells you how it reacts. Metals above hydrogen react with dilute acid; copper, silver and gold do not.
Section 4
Reactions with water, acid and oxygen
- Water: potassium, sodium, lithium and calcium react with cold water to give a metal hydroxide and hydrogen. Magnesium reacts very slowly with cold water but quickly with steam, giving the oxide and hydrogen. Copper does not react.
- Dilute acid: magnesium reacts rapidly, zinc moderately and iron slowly. Copper does not react.
- Oxygen: the more reactive the metal, the more readily it burns. Magnesium burns with a bright white flame to form magnesium oxide.
Use the speed of the reaction (bubbles, heat, flame) to decide a metal's place in the series.
Section 5
Displacement reactions of metals
A more reactive metal displaces a less reactive metal from a solution of its compound.
- iron + copper sulfate → iron sulfate + copper
- Fe + CuSO₄ → FeSO₄ + Cu
The blue solution fades and brown copper forms on the iron. If the metal added is less reactive, there is no reaction: copper added to zinc sulfate does nothing.
Section 6
Uses of metals and alloys
The uses of a metal depend on its properties.
- copper: electrical wires (conductor, ductile)
- aluminium: aircraft and drink cans (low density, resists corrosion)
- gold: jewellery (unreactive, shiny, malleable)
- iron: weak and rusts, so it is made into steel
An alloy is a mixture of a metal with other elements. The atoms of the added element are a different size, so the layers cannot slide, and alloys are harder than pure metals. Steel (iron and carbon), brass (copper and zinc) and bronze (copper and tin) are alloys.
That's the notes covered.
Carry on to the next subtopic.
Exam questions on Properties of metals and non-metals
- A workshop in Jaipur makes jewellery and cooking utensils. The craftspeople hammer gold into thin sheets, draw copper into thin wires and use aluminium for lightweight pans. They also use sulfur in the workshop to make a polish.State two properties of copper that make it suitable for use as electrical wire.2 marks
- A student in Dublin is studying the reactivity series, which lists these metals from most reactive to least reactive: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, copper, silver, gold. She then plans some tests using dilute hydrochloric acid and solutions of metal sulfates.Explain why there is no reaction when copper is added to zinc sulfate solution.2 marks
- A student compares the reactivity of four metals. She adds a 2 cm strip of each metal to 20 cm³ of dilute hydrochloric acid at 20 °C and counts the bubbles produced in one minute. Her results: magnesium about 150 bubbles, zinc about 40, iron about 10 and copper none.Describe the pattern in the results, and identify one variable that the student should keep constant, giving a reason.3 marks
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).