CIE - C4: Metals - 2025

What are the general physical properties of metals?

• High melting and boiling points, Good conductors of heat and electricity, Malleable and Ductile
• Low melting and boiling points, poor conductors of heat and electricity, brittle, non-ductile
• Moderate melting and boiling points, variable conductors of heat and electricity, rigid, non-malleable
• High freezing and evaporation points, moderate conductors of heat and electricity, ductile, non-malleable

Why do metals have relatively high melting and boiling points?

• Metals are giant structures with strong metallic bonding. There is strong electrostatic attraction between the positive ions and the negative electrons so lots of energy is required to break these bonds to change state.
• Metals have weak intermolecular forces, requiring little energy to overcome them.
• Metals have covalent bonding which requires minimal energy to break.
• Metals have ionic bonding which releases energy when broken.

In terms of their structure, why are metals good conductors?

• Metals contain delocalised electrons which are free to move throughout the structure and carry charge.
• Metals have tightly bound electrons within the nucleus, limiting their movement.
• Metals have localized electrons which cannot move freely.
• Metals contain isolated electrons which cannot conduct charge.

Why are metals malleable?

• The positive ions are arranged in uniform rows which are able to slide over one another. This makes a metal malleable.
• The positive ions are arranged in irregular patterns, restricting their movement.
• The positive ions are arranged in rigid, non-flexible structures.
• The positive ions are arranged in random configurations, making the metal brittle.

What is produced when a metal reacts with acid?

• Salt and hydrogen
• Water and carbon dioxide
• Oxygen and carbon
• Chlorine and sulfur

What type of reaction occurs when a metal reacts with an acid? Why does this reaction occur?

• Displacement reaction: The metal is more reactive than hydrogen so it will displace hydrogen and combine with the ion from the acid (e.g. chloride or sulfate ion).
• Combination reaction: The metal and acid combine to form a compound.
• Decomposition reaction: The acid breaks down into its constituent elements.
• Neutralization reaction: The acid and metal neutralize each other's properties.

Write the word equation for the reaction between metals and hydrochloric acid.

• metal+hydrochloric acid→metal chloride+hydrogen
• metal + hydrochloric acid → metal chloride + oxygen
• metal + hydrochloric acid → metal hydroxide + hydrogen
• metal + hydrochloric acid → metal chloride + water

How does the position of a metal in the reactivity series affect whether it will react with a dilute acid?

• If a metal is above hydrogen in the reactivity series, it will react with dilute hydrochloric or sulfuric acid to form a salt and hydrogen.
• The position of a metal in the reactivity series has no effect on its reactivity with acids.
• If a metal is below hydrogen in the reactivity series, it will react with dilute hydrochloric or sulfuric acid to form a salt and hydrogen.
• If a metal is above carbon in the reactivity series, it will react with dilute hydrochloric or sulfuric acid to form a salt and hydrogen.

Why don't metals lower than hydrogen in the reactivity series react with dilute hydrochloric or sulfuric acid?

• They are less reactive than hydrogen so are unable to displace hydrogen from the acid to form a salt.
• They are more reactive than hydrogen so do not need to react with the acid.
• They are less dense than hydrogen so cannot displace it from the acid.
• They are less soluble than hydrogen so cannot react with the acid.

How could you compare how different metals react with an acid?

• 1) Pour the chosen acid into a conical flask. 2) Add the metal to the flask. 3) Record any observations (including the rate at which bubbles are produced). 4) Repeat with different metals and compare.
• 1) Add the metal to the flask. 2) Pour the chosen acid into a conical flask. 3) Record any observations (including the rate at which bubbles are produced). 4) Repeat with different metals and compare.
• 1) Repeat with different metals and compare. 2) Add the metal to the flask. 3) Record any observations (including the rate at which bubbles are produced). 4) Pour the chosen acid into a conical flask.
• 1) Pour the chosen acid into a conical flask. 2) Record any observations (including the rate at which bubbles are produced). 3) Add the metal to the flask. 4) Repeat with different metals and compare.