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Changes around us - physical and chemical

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Changes around us - physical and chemical

Learning Objectives

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Identify and categorize various changes observed in everyday life.
Differentiate between physical and chemical changes.
Analyze whether certain changes can be reversed or not.
Understand the characteristics of physical changes, including the state of substances.
Evaluate the desirability of changes in daily life.

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Revision Notes & Summary

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Changes Around Us: Physical and Chemical

Observations of Changes

Melting ice cubes: Ice turns into water.
Chopping vegetables: Changes shape but not substance.
Boiling water: Water changes state from liquid to gas.
Making popcorn from corn: Corn transforms into a different substance.
Cutting a piece of paper: Changes shape but not substance.
Adding beetroot extract to water: Changes color of the water.
Burning wood: Wood transforms into ash and gases.
Drying wet clothes: Water evaporates, leaving dry clothes.
Making small balls of dough: Changes shape but not substance.
Rolling small balls of dough into chapatis: Changes shape but not substance.

Categories of Changes

Physical Changes: Changes that do not alter the substance's chemical composition (e.g., melting ice, chopping vegetables).
Chemical Changes: Changes that result in the formation of new substances (e.g., burning wood, making popcorn).

Reversibility of Changes

S.No.	Change	The original state can be brought back (Yes/No)
1.	Melting ice cubes	Yes
2.	Chopping vegetables	No
3.	Boiling water	Yes
4.	Making popcorn from corn	No

Inquiry and Curiosity

Questions to Consider:
- Can we arrange these changes into categories?
- Which changes can be reversed and which cannot?

Important Concepts

Fire Triangle: A model illustrating the three essential components for fire to occur:
- Oxygen (Red Side)
- Heat (Orange Side)
- Fuel (Green Base)

Practical Demonstrations

Focusing Light with a Magnifying Glass: Demonstrates light refraction and focal point generation using a convex lens.

Conclusion

Changes around us can be categorized as physical or chemical, and understanding these changes helps us comprehend the world better.

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Practice Test – MCQs, True/False

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Changes around us - physical and chemical

Learning Objectives

Practice, Analyze & Improve 🚀

Revision Notes & Summary

Changes Around Us: Physical and Chemical

Observations of Changes

Categories of Changes

Reversibility of Changes

Inquiry and Curiosity

Important Concepts

Practical Demonstrations

Conclusion

Do you belong in the Top 10%?

Practice Test – MCQs, True/False