Bitter, Astringent, Slippery
- Bases turn RED litmus BLUE, methyl orange yellow, phenolphthalein pink
- Sodium hydroxide, potassium hydroxide, soap, ash, lime, antacid
- An ALKALI is simply a base that dissolves in water
- Slippery because a base turns the oil on your skin into soap
Presenter notes: Open with the question you deliberately left hanging at the end of the acid lesson. Write two lines on the board: soap on an ant sting, vinegar on a wasp sting. Ask why the treatment flips, when both are just insect stings on the same arm. Nobody can answer it yet, and that is the point. Tell them that by the end of the period one sentence will explain both of those, plus the tablet their grandmother takes for gastritis, plus why ash is spread on a field, plus why roti rises. Five things, one idea.