Activity 9.1: Peanut Skin Separation
Task: Rub roasted peanuts between palms and blow on them.
- Observation: The red skins (light) fly away, while the heavy nuts stay in your hand.
- Concept: This mimics Winnowing. Air separates light components from heavy ones.
Activity 9.2: Salt Art
Task: Dissolve salt in water, put drops on black paper, and let it dry.
- Observation: White patches appear on the paper after water disappears.
- Concept: Evaporation. The water turns to vapour, leaving the solid salt behind.
Activity 9.3: Heating Salt Water
Task: Heat salt solution in a china dish.
- Observation: Water boils away completely. White powder is left.
- Concept: Faster Evaporation using heat energy to recover dissolved solids.
Activity 9.4: Making a Filter Cone
Task: Fold a circular filter paper into a cone and pour muddy water through it.
- Observation: Clear water collects in the flask. Mud stays on the paper.
- Concept: Filtration. The pores of the paper are smaller than mud particles.
Activity 9.5: DIY Water Filter
Task: Design a low-cost water filter.
- Suggestion: Use a plastic bottle cut in half upside down. Layer it with:
- Cotton (bottom)
- Fine Sand
- Gravel/Charcoal (top)
- Result: Dirty water poured on top comes out cleaner at the bottom.
Activity 9.6: Classification Game
Task: Classify various separation tasks (e.g., separating tea leaves, churning curd) onto slips of paper.
- Goal: To reinforce identifying which method matches which real-life scenario.
- Key Matches:
- Tea leaves → Filtration
- Butter → Churning
- Peanuts → Handpicking/Winnowing
- Iron nails → Magnetic Separation