1.2.10
Reactivity of Alkaline Earth Metals
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Reactivity of Group 2 Metals
The reactivity of group 2 metals increases down the group. This can be illustrated by their reactions with oxygen, water, and dilute acids.

Trends in reactivity
- The reactivity of group 2 metals increases down the group.
- The ionisation energies needed decrease down the group because increased shielding from extra shells of electrons and a greater distance from the nucleus makes it easier to remove an outer electron.
- Both first and second ionisation energies decrease down the group. The second ionisation energy is greater than the first ionisation energy within an element.
 2.1.4.3 - Covalent bonding in oxygen (1),h_400,q_80,w_640.png)
Reaction with oxygen
- Group 2 elements react with oxygen in the air to form metal oxides, For example:
- 2Mg + O2 → 2MgO
- The elements react more readily with oxygen down the group because of the decrease in ionisation energies.

Reaction with water
- Group 2 metals react with water to form metal hydroxides. For example:
- Mg + 2H2O → Mg(OH)2 + H2
- Reactivity increases as you go down Group 2. This is because the lower elements have lower ionisation energies.
- Beryllium is an exception. If beryllium were to lose two electrons it would be tiny and have a very high charge density. This would make it unstable and so beryllium doesn't react with water.

Reaction with dilute acids
- Group 2 metals react with dilute acids to produce a salt and hydrogen. For example:
- Ca + H2SO4 → CaSO4 + H2
- Reactivity increases down the group because of the decrease in ionisation energies.
- The salts produced become less soluble as you go down the group.
Group 2 Oxides Reacting with Water
Group 2 oxides react with water to form metal hydroxides.

Group 2 oxides and water
- Group 2 oxides steadily react with water.
- The reaction produces a metal hydroxide salt. The salt dissociates into metal ions and hydroxide ions, giving the solution an alkaline pH.

Solubility down the group
- Group 2 hydroxides become more soluble down the group.
- This means that the solutions become more strongly alkaline the further down Group 2 you go.

Exceptions to the rule
- Beryllium oxide does not react with water.
- Magnesium oxide reacts but very slowly.
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model1.1.2Electron Shells, Sub-Shells & Orbitals1.1.3Ionic Bonding1.1.4Representing Ionic Bonds1.1.5Covalent Bonding1.1.6Representing Covalent Bonds1.1.7Metallic Bonding1.1.8Intermolecular Forces1.1.9Intermolecular Forces 21.1.10End of Topic Test - Bonding1.1.11Relative Masses1.1.12The Mole1.1.13Molar Calculations1.1.14Molar Calculations 21.1.15Empirical & Molecular Formulae1.1.16Balanced Equations1.1.17Percentage Yield1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table1.2.2Ionisation Energy1.2.3Factors Affecting Ionisation Energies1.2.4Trends of Ionisation1.2.5Trends in the Periodic Table1.2.6Polarity1.2.7Metals & Non-Metals1.2.8Alkali Metals1.2.9Alkaline Earth Metals1.2.10Reactivity of Alkaline Earth Metals1.2.11Redox1.2.12Transition Metals1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange1.5.2Blood Vessels1.5.3Atherosclerosis1.5.4Skeletal Muscle1.5.5Slow & Fast Twitch Fibres1.5.6Neurones1.5.7Speed of Transmission1.5.8Action Potentials1.5.9End of Topic Test - Neurones & Action Potentials1.5.10Synapses1.5.11Types of Synapse1.5.12Medical Application1.5.13End of Topic Test - Synapses1.5.14Chemical Brain Imbalances1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System4.5.2Blood Vessels4.5.3Blood Transfusion & the ABO Rhesus System4.5.4The Heart4.5.5The Cardiac Cycle4.5.6Cardiac Output4.5.7Coordination of Heart Action4.5.8Heart Dissection4.5.9Controlling Heart Rate4.5.10Electrocardiograms4.5.11Cardiovascular Disease4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency4.9.2Work & Energy4.9.3Conservation of Energy4.9.4Pressure4.9.5First Law of Thermodynamics4.9.6Second Law of Thermodynamics4.9.7Heat Engines, Heat Pumps & Refrigerators4.9.8Non-Flow Processes4.9.9p-V Diagrams4.9.10Ideal Gases4.9.11Ideal Gases 24.9.12Thermal Energy Transfer4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
Jump to other topics
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model1.1.2Electron Shells, Sub-Shells & Orbitals1.1.3Ionic Bonding1.1.4Representing Ionic Bonds1.1.5Covalent Bonding1.1.6Representing Covalent Bonds1.1.7Metallic Bonding1.1.8Intermolecular Forces1.1.9Intermolecular Forces 21.1.10End of Topic Test - Bonding1.1.11Relative Masses1.1.12The Mole1.1.13Molar Calculations1.1.14Molar Calculations 21.1.15Empirical & Molecular Formulae1.1.16Balanced Equations1.1.17Percentage Yield1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table1.2.2Ionisation Energy1.2.3Factors Affecting Ionisation Energies1.2.4Trends of Ionisation1.2.5Trends in the Periodic Table1.2.6Polarity1.2.7Metals & Non-Metals1.2.8Alkali Metals1.2.9Alkaline Earth Metals1.2.10Reactivity of Alkaline Earth Metals1.2.11Redox1.2.12Transition Metals1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange1.5.2Blood Vessels1.5.3Atherosclerosis1.5.4Skeletal Muscle1.5.5Slow & Fast Twitch Fibres1.5.6Neurones1.5.7Speed of Transmission1.5.8Action Potentials1.5.9End of Topic Test - Neurones & Action Potentials1.5.10Synapses1.5.11Types of Synapse1.5.12Medical Application1.5.13End of Topic Test - Synapses1.5.14Chemical Brain Imbalances1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System4.5.2Blood Vessels4.5.3Blood Transfusion & the ABO Rhesus System4.5.4The Heart4.5.5The Cardiac Cycle4.5.6Cardiac Output4.5.7Coordination of Heart Action4.5.8Heart Dissection4.5.9Controlling Heart Rate4.5.10Electrocardiograms4.5.11Cardiovascular Disease4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency4.9.2Work & Energy4.9.3Conservation of Energy4.9.4Pressure4.9.5First Law of Thermodynamics4.9.6Second Law of Thermodynamics4.9.7Heat Engines, Heat Pumps & Refrigerators4.9.8Non-Flow Processes4.9.9p-V Diagrams4.9.10Ideal Gases4.9.11Ideal Gases 24.9.12Thermal Energy Transfer4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
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