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Science and Technology, Grade 8
Bases and Alkalis
Oxides and hydroxides of metals · Strong and weak alkalis · Physical and chemical properties
What This Lesson Covers
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Telling a base from an alkali
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Recognising strong and weak alkalis
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Testing the physical properties of a base
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Writing the three chemical properties
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Naming the everyday uses of bases
How to Recognise One
From Base to Alkali
METAL
Look for a metal in the compound.
JOINED
If oxygen or a hydroxide group is joined to it, the compound is a base.
DISSOLVE
If that base dissolves in water, it is an alkali.
IONS
The alkali then releases hydroxide ions into the solution.
Presenter notes: Open by asking the class why a hand with soap on it feels slippery. Today's lesson answers that.