The Three Types of Chemical Bond
Master The Three Types of Chemical Bond for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Metal + non-metal gives ionic bonding, non-metal + non-metal gives covalent bonding, and metal atoms together give metallic bonding.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
There are three types of strong chemical bond: ionic, covalent and metallic. Which one forms depends on the types of element involved.
Ionic bonding occurs between a metal and a non-metal. Electrons are transferred from the metal to the non-metal, forming oppositely charged ions that attract each other strongly.
Covalent bonding occurs between non-metals only. Atoms share pairs of electrons. Metallic bonding occurs in metals and alloys, where atoms share delocalised electrons that are free to move throughout the structure. Identifying the elements involved is always the first step in a bonding question.
Revision notes
Ionic bonding
Occurs between a metal and a non-metal.
Electrons are transferred from the metal atom to the non-metal atom. The metal forms a positive ion and the non-metal a negative ion, and the oppositely charged ions attract each other strongly.
Covalent bonding
Occurs between non-metals only.
Atoms share pairs of electrons so that each achieves a full outer shell. The shared pair is attracted to both nuclei, holding the atoms together.
Metallic bonding
Occurs in metals and alloys.
The atoms share delocalised electrons, which are free to move throughout the whole structure. This gives metals their conductivity and their ability to be bent and shaped.
Key points
- There are three types of strong bond.
- Ionic bonding is between a metal and a non-metal.
- Ionic bonding involves the transfer of electrons.
- Covalent bonding is between non-metals only.
- Covalent bonding involves shared pairs of electrons.
- Metallic bonding involves delocalised electrons.
Worked examples
Example 1
State the type of bonding in magnesium oxide and explain your answer. [2 marks]
Model answer
Ionic bonding (1 mark), because magnesium is a metal and oxygen is a non-metal, so electrons are transferred from the magnesium to the oxygen (1 mark).
Example 2
Explain the difference between ionic and covalent bonding. [2 marks]
Model answer
In ionic bonding electrons are transferred from a metal to a non-metal, forming oppositely charged ions (1 mark). In covalent bonding, non-metal atoms share pairs of electrons (1 mark).
Example 3
Explain what is meant by delocalised electrons in a metal. [2 marks]
Model answer
The outer shell electrons of the metal atoms are no longer associated with a particular atom (1 mark) and are free to move throughout the whole structure (1 mark).
Common mistakes
Saying covalent bonding occurs between metals.
Covalent bonding is between non-metals only.
Saying electrons are shared in ionic bonding.
They are transferred. Sharing occurs in covalent bonding.
Forgetting to identify the elements first.
Whether each element is a metal or non-metal determines the bond type.
Confusing delocalised with shared electrons.
Delocalised electrons move throughout the whole structure, not between two atoms.
Exam tips
- Identify whether each element is a metal or non-metal first.
- Use transferred for ionic and shared for covalent.
- Say delocalised and free to move for metallic bonding.
- Justify your answer by naming the elements involved.
Key terms
- Ionic bonding
- Bonding by the transfer of electrons between a metal and non-metal.
- Covalent bonding
- Bonding by shared pairs of electrons between non-metals.
- Metallic bonding
- Bonding involving delocalised electrons in a metal.
- Delocalised electron
- An electron free to move throughout a structure.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.