Metallic bonding — KCSE Chemistry

KCSE Chemistry · 58 practice questions · 3 syllabus objectives

20 easy22 medium16 hard

What You'll Learn

Key learning outcomes for this topic, aligned to the KNEC KCSE syllabus.

Describe metallic bonding using the electron sea model

Relate the properties of metals (electrical conductivity, malleability, ductility, lustre) to the metallic bond

Metallic bonding

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easySHORT ANSWER3 marks

Explain how the electron sea model accounts for the high thermal conductivity observed in metals. (3 marks)

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Part (a) — 3 marks

Delocalised electrons can move freely throughout the metal lattice, allowing them to transfer thermal energy efficiently. (1 mk)

The movement of these electrons carries kinetic energy, which is transferred as heat. (1 mk)

The close packing of metal ions facilitates rapid energy transfer between ions and electrons, enhancing thermal conductivity. (1 mk)

easySHORT ANSWER4 marks

Define metallic bonding and describe the role of the electron sea model in explaining the properties of metals. (4 marks)

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Part (a) — 1 mark

Metallic bonding is the electrostatic attraction between positively charged metal ions and a sea of delocalised electrons. (1 mk)

Part (b) — 3 marks

The sea of delocalised electrons allows for the flow of electrical current through the metal. (1 mk)

The delocalised electrons enable atoms to slide past one another, contributing to ductility. (1 mk)

The presence of the electron sea model accounts for the malleability and conductivity of metals. (1 mk)

easySHORT ANSWER2 marks

State two reasons why metals are malleable due to their metallic bonding. (2 marks)

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Part (a) — 2 marks

The layers of metal ions can slide over each other without breaking the metallic bond (1 mk)

Delocalised electrons can adjust to the new positions of the metal ions, maintaining the metallic bond (1 mk)

State how the structure of metals contributes to their ability to conduct electricity. (2 marks)