Matter Around Us — Class 6 Science (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 6 Science, Term 1 — Chapter 3. Matter and how to separate mixtures.
1. About this chapter
This chapter covers what matter is, pure substances and mixtures, and the methods of separating mixtures.
2. Matter
- Matter is anything that has mass and occupies space. So 200 mL of water poured into a 400 mL bowl still has a volume of 200 mL — matter takes up a definite space. A light ray is not matter (it has no mass).
- A pure substance has only one kind of particle; a mixture has two or more substances mixed together. Air is a mixture of gases, not a pure substance.
3. Methods of separating mixtures
| Method | Use / example |
|---|---|
| Hand-picking | removing big bits by hand — e.g. watermelon seeds, stones from rice |
| Winnowing | wind separates lighter and heavier particles — e.g. grain from husk, dust or paper bits from pulses (needs air) |
| Sieving | separates solid particles of different sizes — e.g. bran from flour |
| Filtration | separates an insoluble solid from a liquid — e.g. paneer (cheese) from milk |
| Decantation | pouring off the liquid — e.g. water from washed pulses |
| Churning | separates butter from curd |
4. Worked examples
Example 1. How is grain separated from husk? By winnowing (using air/wind).
Example 2. How is butter separated from curd? By churning.
Example 3. How is paneer separated from milk? By filtration (using a strainer).
5. Book-back questions (Samacheer Kalvi)
I. Choose the correct answer
- Which is not made of matter? — (a) water / (b) a light ray. Ans: (b) a light ray.
- 200 mL of water poured into a 400 mL bowl has a volume of — (a) 400 mL / (b) 200 mL. Ans: (b) 200 mL.
- Lighter impurities mixed with rice are removed by — (a) hand-picking / (b) winnowing. Ans: (b) winnowing.
- A solid–liquid mixture is best separated by — (a) sieving / (b) filtration. Ans: (b) filtration.
II. True or False 5. A strainer is a kind of sieve used to separate a liquid from a solid. — True. 6. Grain and husk can be separated by winnowing. — True. 7. Air is a pure substance. — False (it is a mixture of gases). 8. Butter is separated from curd by sedimentation. — False (by churning).
III. Answer briefly 9. How are bits of paper separated from pulses? — By winnowing, as the light paper is blown away and the heavier pulses fall close by. 10. Which method separates bran from flour? — Sieving.
6. Common mistakes
- Mistake: Calling air a pure substance. Fix: Air is a mixture of gases.
- Mistake: Using filtration to separate butter from curd. Fix: Butter is separated by churning.
- Mistake: Thinking light is matter. Fix: A light ray has no mass, so it is not matter.
7. Quick revision
- Term 1 · Ch 3 · matter around us.
- Matter has mass and occupies space (light is not matter); air is a mixture of gases.
- Separation methods: hand-picking (seeds), winnowing (grain/husk, uses air), sieving (bran/flour), filtration (paneer/milk), decantation (water from pulses), churning (butter from curd).
