Bonding Basics
How do atoms join up? Meet the three chemical bonds: ionic, covalent and metallic. Learn which elements form each, whether electrons are transferred or shared, and the structures they build.
Get the method right under pressure
Free interactive practice on the steps that lose marks under exam pressure.
Start revising freeWhat you'll cover
What holds atoms together?
Almost nothing exists as lone atoms. Atoms join using chemical bonds, and there are three kinds. Which bond forms depends on which elements meet: ionic (a metal with a non-metal), covalent (non-metals together) and metallic (metals together). This module shows how each one works.
Four words to know
These words describe what the electrons do in each type of bond.
Match the term
- Ionic bond
- Covalent bond
- Metallic bond
- Ion
- Electrons transferred from a metal to a non-metal
- Electrons shared between non-metal atoms
- Positive ions in a sea of delocalised electrons
- A charged atom
Which bond?
Which type of bond forms between a metal and a non-metal?
- Ionic
- Covalent
- Metallic
- No bond forms
Transfer or share?
The big difference between the first two bonds is what happens to the electrons.
Match the particle idea
- Positive ion
- Negative ion
- Delocalised electrons
- Giant ionic lattice
- An atom that has lost electrons
- An atom that has gained electrons
- Free-moving electrons in a metal
- A regular repeating arrangement of many ions
The grade 9 rule: name the delocalised electrons
Describe metallic bonding as positive ions held in a sea of delocalised electrons. Naming the delocalised electrons explicitly is what earns the marks, and it explains later why metals conduct electricity and can be bent into shape.
Ionic, covalent and metallic
In _____ bonding a metal gives electrons to a non-metal, forming charged _____. In _____ bonding, non-metal atoms _____ pairs of electrons. In metallic bonding, positive ions sit in a sea of _____ electrons.
Spot the covalent substances
Which of these substances are held together by covalent bonds? Choose all that apply.
- Water
- Chlorine gas
- Carbon dioxide
- Sodium chloride
- Copper metal
Find the ionic bonding
Tap the two statements that describe ionic bonding.
- Electrons are transferred from a metal to a non-metal.
- The compound forms a giant lattice of positive and negative ions.
- Atoms share pairs of electrons to make molecules.
- Positive ions sit in a sea of delocalised electrons.
How an ionic bond forms
Put the steps of ionic bond formation into the right order.
- A metal atom loses its outer electrons
- A non-metal atom gains those electrons
- Both atoms become charged ions
- Oppositely charged ions attract strongly
- Many ions build a giant lattice
Why metals conduct
Why can a metal conduct electricity?
- It has delocalised electrons that are free to move
- Its ions are negatively charged
- It shares pairs of electrons
- It has no bonds between its atoms
Which bond forms?
For each pair of elements, choose the type of bond that forms.
- Sodium, a metal, reacts with chlorine, a non-metal. What bond forms?
- Two oxygen atoms, both non-metals, join together. What bond forms?
- A block of pure iron, a metal. What bonding holds it together?
How an ionic bond forms
Explain how an ionic bond forms between a metal and a non-metal. Describe what happens to the electrons and what is formed.
- Say which atom loses electrons and which gains them
- Name the charged particles that form
- Describe how the ions are held together