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Edexcel A Level Chemistry

Groups 1 and 2

The s-block metals are the clearest example of trends down a group. These pages explain the trends in atomic radius, ionisation energy and reactivity, the reactions of the elements and their oxides, hydroxides and carbonates, the solubility and thermal stability patterns, flame colours and the tests for ions. Edexcel Topic 4A examines Group 2 only. The Group 1 metals are kept in the tables because comparing the two groups is the quickest way to see the patterns, but questions will be set on magnesium to barium.

Exam Papers
Paper 1
9CH0/01
Specification Points
4.1 – 4.15
9 points covered
Sub-topics
5 lessons
Revision notes available
Exam Board
Edexcel
Pearson 9CH0

Revision Notes

5 revision notes, in the order the specification teaches them.

A column of atoms growing larger down a group
1

Trends Down Groups 1 and 2

The trends down Group 2: atomic radius, ionisation energies, melting points and the increase in reactivity down the group.

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A metal ribbon burning in tongs
2

Reactions of the Group 1 and 2 Elements

The reactions of the Group 2 elements with oxygen, chlorine, water, steam and dilute acids, with equations, observations and redox analysis.

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A white oxide dissolving to give an alkaline solution
3

Oxides, Hydroxides and Carbonates

Group 2 oxides, hydroxides and carbonates: reactions with water and acids, pH trend, and uses of Ca(OH)₂, Mg(OH)₂ and CaCO₃.

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A thick white precipitate falling in a test tube
4

Solubility Trends and the Sulfate Test

Group 2 solubility trends: hydroxides and sulfates, Mg(OH)₂ and BaSO₄, the acidified barium chloride test for sulfate ions and barium meals.

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Three flames in crimson, yellow and lilac
5

Thermal Stability and Flame Colours

Thermal stability of Group 1 and 2 nitrates and carbonates, polarisation by the cation, the experiments, and flame colours explained by electron transitions.

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Summary Map

Download, print and revise the key facts of this topic at a glance.

Summary map

Download, print and revise the key facts of this topic at a glance.

Illustration of a summary map: compounds joined by reaction arrows
Summary map · PDF

Groups 1 and 2 Map

Edexcel A Level Chemistry · Topic 4 Inorganic Chemistry and the Periodic Table · Groups 1 and 2

The whole section on one A4 page: trends down the groups, reactions of the metals, oxides and hydroxides, thermal stability, flame colours, and tests for ions.

Download the map6 key ideas + a data table · A4 portrait · print ready

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Revision Game

Match reagents to products, with your board's reagents and conditions.

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Study Cards

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Specification

Every specification point in this topic, in the exam board's own words. Rate how confident you are with each one.

Official Pearson Edexcel documentsSpecification (opens the Pearson Edexcel website in a new tab)Data booklet (opens the Pearson Edexcel website in a new tab)

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4

  1. A.1

    understand reasons for the trend in ionisation energy down Group 2

    Revise
  2. A.2

    understand reasons for the trend in reactivity of the Group 2 elements down the group

    Revise
  3. A.3 a

    know the reactions of Mg to Ba with oxygen

    Revise
  4. A.3 b

    know the reactions of Mg to Ba with chlorine

    Revise
  5. A.3 c

    know the reactions of Mg to Ba with water

    Revise
  6. A.4 a

    know the reactions of Group 2 oxides with water

    Revise
  7. A.4 b

    know the reactions of Group 2 oxides with dilute acid

    Revise
  8. A.4 c

    know the reactions of Group 2 hydroxides with dilute acid

    Revise
  9. A.5 a

    know the trends in solubility of Group 2 hydroxides

    Revise
  10. A.5 b

    know the trends in solubility of Group 2 sulfates

    Revise
  11. A.6 a

    understand reasons for trends in thermal stability of Group 1 nitrates in terms of size and charge of cations

    Revise
  12. A.6 b

    understand reasons for trends in thermal stability of Group 2 nitrates in terms of size and charge of cations

    Revise
  13. A.6 c

    understand reasons for trends in thermal stability of Group 1 carbonates in terms of size and charge of cations

    Revise
  14. A.6 d

    understand reasons for trends in thermal stability of Group 2 carbonates in terms of size and charge of cations

    Revise
  15. A.7 a

    understand formation of flame colours by Group 1 compounds in terms of electron transitions

    Revise
  16. A.7 b

    understand formation of flame colours by Group 2 compounds in terms of electron transitions

    Revise
  17. A.7 c

    know the flame colours for Group 1 compounds

    Revise
  18. A.7 d

    know the flame colours for Group 2 compounds

    Revise
  19. A.8i

    understand experimental procedures to show: patterns in thermal decomposition of Group 1 and 2 nitrates and carbonates

    Revise
  20. C.15ii

    know reactions, including ionic equations where appropriate, for identifying: sulfate ions, SO42-, using acidified barium chloride solution

    Revise