2.4.2
Formation of Ions & Ionic Bonds
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Formation of Ions and Ionic Bonds
Ions are charged atoms (or groups) formed by losing (positive) or gaining (negative) electrons for stability. Opposite charges attract, forming strong ionic bonds that build crystal lattices.

What are ions?
- Ions are atoms or groups of atoms that carry an electric charge.
- Positive ions have more protons than electrons.
- Negative ions have more electrons than protons.
- Ions form to achieve a full outer electron shell, making atoms more stable.

Formation of positive ions (cations)
- Atoms of metals lose electrons to become positive ions.
- Losing electrons reduces the number of negative charges.
- For example, sodium (Na) loses one electron to form Na+.
- This electron loss helps the atom have a full outer shell like noble gases.

Formation of negative ions (anions)
- Atoms of non-metals gain electrons to become negative ions.
- Gaining electrons increases the number of negative charges.
- For example, chlorine (Cl) gains one electron to form Cl-.
- This electron gain helps the atom have a full outer shell like noble gases.
 2.1.3.1 - Ionic lattice represented using both the space-filling model and ball and stick model,h_400,q_80,w_640.jpg)
How ionic bonds form
- Ionic bonds form between positive metal ions and negative non-metal ions.
- Opposite charges attract and hold the ions together.
- This attraction creates a strong ionic bond.
- Ionic compounds form crystal lattices due to these bonds.
1States of Matter
1.1Solids, Liquids, & Gases
2Atoms, Elements & Compounds
2.1Elements, Compounds & Mixtures
2.2Atomic Structure & the Periodic Table
2.3Isotopes
2.4Ions & Ionic Bonds
2.5Simple Molecules & Covalent Bonds
2.6Giant Covalent Structures
2.7Metallic Bonding
3Stoichometry
3.1Formulae
3.2Relative Masses of Atoms & Molecules
3.3The Mole & the Avogadro Constant
3.3.1Introducing Moles3.3.2Amounts of Substances3.3.3Moles & Equations3.3.4Calculations Involving Gases3.3.5Calculating Stoichiometric Reacting Masses3.3.6Calculating the Moles of Solute3.3.7Calculating Empirical Formula3.3.8Chemical Equations3.3.9Percentage Yield3.3.10Calculating Yield3.3.11Percentage Purity
4Electrochemistry
4.1Electrolysis
4.1.1Electrolytic Process4.1.2Electrolysis Examples4.1.3Electrolysis of a Binary Compound in Molten State4.1.4Electroplating4.1.5Transfer of Charge During Electrolysis4.1.6Electrolysis of Aqueous Solutions4.1.7Electrolysis of Copper Sulfate4.1.8Electrolysis of Halide Compounds4.1.9Half-Equations4.1.10Combustion of Hydrocarbons
4.2Hydrogen–Oxygen Fuel Cells
5Chemical Energetics
6Chemical Reactions
6.1Physical & Chemical Changes
6.2Rate of Reaction
6.3Reversible Reactions & Equilibrium
6.3.1Reversible Reactions6.3.2Conditions & Equilibrium6.3.3Dynamic Equilibrium6.3.4Changing Conditions - Heat & Water Effects6.3.5Factors Affecting Equilibria - Temperature6.3.6Factors Affecting Equilibria - Pressure6.3.7Factors Affecting Equilibria - Concentration6.3.8The Haber Process6.3.9The Haber Process Equation
7Acids, Bases & Salts
7.1The Characteristic Properties of Acids & Bases
7.1.1Acids & Alkali7.1.2Reactions of Metals with Acids7.1.3Reactions of Bases with Acids7.1.4Reactions of Carbonates with Acids7.1.5Identifying Acids7.1.6Properties & Effects of Acids7.1.7Properties of Bases - Reactions with Acids & Salts7.1.8Properties of Alkalis & Indicators7.1.9Strong vs Weak Acids7.1.10Strong vs Weak Bases7.1.11Understanding Universal Indicator Paper7.1.12Acids, Bases & the Neutralisation Reaction
8The Periodic Table
8.1Arrangement of Elements
8.2Group I Properties
8.3Group VII Properties
8.4Transition Elements
8.5Noble Gases
9Metals
9.1Properties of Metals
9.2Uses of Metals
9.3Alloys & Their Properties
9.4Reactivity Series
9.5Corrosion of Metals
9.6Extraction of Metals
10Chemistry of the Environment
10.1Water
10.2Fertilisers
11Organic Chemistry
11.1Formulae, Functional Groups & Terminology
11.2Naming Organic Compounds
11.3Fuels
11.4Alkanes
11.5Alkenes
11.6Alcohols
11.7Carboxylic Acids
11.8Polymers
11.8.1Polymers11.8.2Problems With Polymers11.8.3Polymers & Plastics11.8.4Problems with Plastics11.8.5Condensation Polymerisation11.8.6Condensation Polymerisation Examples11.8.7Addition Polymerisation11.8.8Addition Polymerisation Examples11.8.9Structure of Polymers11.8.10Natural Polyamides - Proteins & Amino Acids
12Experimental Techniques & Chemical Analysis
12.1Experimental Design
12.2Acid-base Titrations
12.3Chromatography
12.4Separation & Purification
12.5Identification of Ions & Gases
12.5.1Testing Aqueous Cations 112.5.2Testing Aqueous Cations 212.5.3Testing Cations - Flame Tests12.5.4Testing Cations12.5.5Testing for Aqueous Cations12.5.6Testing Anions - Sulfates12.5.7Testing Anions - Nitrates12.5.8Testing Gases - Hydrogen12.5.9Testing Gases - Oxygen12.5.10Testing Gases - Carbon Dioxide12.5.11Testing Gases - Chlorine12.5.12Identifying Gases
Jump to other topics
1States of Matter
1.1Solids, Liquids, & Gases
2Atoms, Elements & Compounds
2.1Elements, Compounds & Mixtures
2.2Atomic Structure & the Periodic Table
2.3Isotopes
2.4Ions & Ionic Bonds
2.5Simple Molecules & Covalent Bonds
2.6Giant Covalent Structures
2.7Metallic Bonding
3Stoichometry
3.1Formulae
3.2Relative Masses of Atoms & Molecules
3.3The Mole & the Avogadro Constant
3.3.1Introducing Moles3.3.2Amounts of Substances3.3.3Moles & Equations3.3.4Calculations Involving Gases3.3.5Calculating Stoichiometric Reacting Masses3.3.6Calculating the Moles of Solute3.3.7Calculating Empirical Formula3.3.8Chemical Equations3.3.9Percentage Yield3.3.10Calculating Yield3.3.11Percentage Purity
4Electrochemistry
4.1Electrolysis
4.1.1Electrolytic Process4.1.2Electrolysis Examples4.1.3Electrolysis of a Binary Compound in Molten State4.1.4Electroplating4.1.5Transfer of Charge During Electrolysis4.1.6Electrolysis of Aqueous Solutions4.1.7Electrolysis of Copper Sulfate4.1.8Electrolysis of Halide Compounds4.1.9Half-Equations4.1.10Combustion of Hydrocarbons
4.2Hydrogen–Oxygen Fuel Cells
5Chemical Energetics
6Chemical Reactions
6.1Physical & Chemical Changes
6.2Rate of Reaction
6.3Reversible Reactions & Equilibrium
6.3.1Reversible Reactions6.3.2Conditions & Equilibrium6.3.3Dynamic Equilibrium6.3.4Changing Conditions - Heat & Water Effects6.3.5Factors Affecting Equilibria - Temperature6.3.6Factors Affecting Equilibria - Pressure6.3.7Factors Affecting Equilibria - Concentration6.3.8The Haber Process6.3.9The Haber Process Equation
7Acids, Bases & Salts
7.1The Characteristic Properties of Acids & Bases
7.1.1Acids & Alkali7.1.2Reactions of Metals with Acids7.1.3Reactions of Bases with Acids7.1.4Reactions of Carbonates with Acids7.1.5Identifying Acids7.1.6Properties & Effects of Acids7.1.7Properties of Bases - Reactions with Acids & Salts7.1.8Properties of Alkalis & Indicators7.1.9Strong vs Weak Acids7.1.10Strong vs Weak Bases7.1.11Understanding Universal Indicator Paper7.1.12Acids, Bases & the Neutralisation Reaction
8The Periodic Table
8.1Arrangement of Elements
8.2Group I Properties
8.3Group VII Properties
8.4Transition Elements
8.5Noble Gases
9Metals
9.1Properties of Metals
9.2Uses of Metals
9.3Alloys & Their Properties
9.4Reactivity Series
9.5Corrosion of Metals
9.6Extraction of Metals
10Chemistry of the Environment
10.1Water
10.2Fertilisers
11Organic Chemistry
11.1Formulae, Functional Groups & Terminology
11.2Naming Organic Compounds
11.3Fuels
11.4Alkanes
11.5Alkenes
11.6Alcohols
11.7Carboxylic Acids
11.8Polymers
11.8.1Polymers11.8.2Problems With Polymers11.8.3Polymers & Plastics11.8.4Problems with Plastics11.8.5Condensation Polymerisation11.8.6Condensation Polymerisation Examples11.8.7Addition Polymerisation11.8.8Addition Polymerisation Examples11.8.9Structure of Polymers11.8.10Natural Polyamides - Proteins & Amino Acids
12Experimental Techniques & Chemical Analysis
12.1Experimental Design
12.2Acid-base Titrations
12.3Chromatography
12.4Separation & Purification
12.5Identification of Ions & Gases
12.5.1Testing Aqueous Cations 112.5.2Testing Aqueous Cations 212.5.3Testing Cations - Flame Tests12.5.4Testing Cations12.5.5Testing for Aqueous Cations12.5.6Testing Anions - Sulfates12.5.7Testing Anions - Nitrates12.5.8Testing Gases - Hydrogen12.5.9Testing Gases - Oxygen12.5.10Testing Gases - Carbon Dioxide12.5.11Testing Gases - Chlorine12.5.12Identifying Gases
Practice questions on Formation of Ions & Ionic Bonds
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- 1What is the definition of an ion?Multiple choice
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