Metals

Syllabus tag: KCSE | Chemistry | Form 4 | Topic 22 Metals

Lesson objectives

By the end of this topic, you should be able to:

• Describe the occurrence of metals and the general principles of extraction.
• Describe the extraction of sodium, aluminium, zinc, iron and copper.
• Relate the method of extraction to the position in the reactivity series.
• Describe the properties, alloys, uses and environmental effects of metals.

Summary

The method of extraction depends on the reactivity of the metal. Very reactive metals are obtained by electrolysis of the molten compound; moderately reactive ones by reduction with carbon; and unreactive ones occur native or need only roasting. Alloys improve properties, and mining carries significant environmental costs.