Chemical Families

Syllabus tag: KCSE | Chemistry | Form 2 | Topic 7 Chemical Families

Lesson objectives

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

• Describe the alkali metals and explain the trend in their reactivity.
• Describe the alkaline earth metals and compare them with Group I.
• Describe the halogens and their displacement reactions.
• Describe the noble gases and the general properties of transition elements.

Summary

Elements in the same group have the same number of outer electrons and therefore similar chemistry. Group I alkali metals and Group II alkaline earth metals lose electrons, and become more reactive down the group. Group VII halogens gain an electron and become less reactive down the group. Group VIII noble gases are unreactive.