Science · Class 6 · Chapter 6

Materials Around Us

• Material — Any substance used to create an object.
• Classification — Grouping by a shared property.
• Lustrous / Non-lustrous — Shiny / not shiny.
• Hard / Soft — Hard to / easy to compress or scratch.
• Transparent / Opaque — Clear to see through / not at all.
• Translucent — Partly, unclearly see-through.
• Soluble / Insoluble — Dissolves / does not dissolve in water.
• Matter — Anything with mass that occupies space.

Chapter 6 · Concept 1 of 8

Observing Objects Around Us

• Any substance used to create an object is called a material — paper, wood, cloth, glass, metal, clay.
• Same object, different materials — A tumbler can be made of steel, plastic, or glass — the choice depends on the object's purpose and the material's properties.
• An ancient craft — Indian pottery-making goes back 7,000–8,000 years — clay was carefully selected, cleaned, shaped, and baked into terracotta.

Chapter 6 · Concept 2 of 8

How Do We Group Materials?

• Arranging objects into groups based on a common property is called classification. Different people may pick different features — shape, colour, hardness — as the basis for grouping.
• Classification — The method of arranging objects or materials into groups, based on a property they share.

Chapter 6 · Concept 3 of 8

Lustrous and Non-lustrous Materials

• Lustrous — Materials with a shiny surface — usually metals, like iron, copper, zinc, aluminium, and gold.
• Non-lustrous — Materials without shine — paper, wood, rubber, jute. Note: not everything shiny is a metal — some materials are polished or coated to shine.

Chapter 6 · Concept 4 of 8

Hard and Soft Materials

• Hard — Difficult to compress or scratch — e.g. stone, iron.
• Soft — Compresses or scratches easily — e.g. sponge, eraser. Hardness is relative: rubber is harder than sponge, but softer than iron.

Chapter 6 · Concept 5 of 8

Transparent, Translucent, and Opaque

• Transparent — You can see clearly through it — glass, water, air.
• Translucent — You can see through it, but not clearly — butter paper, frosted glass.
• Opaque — Nothing can be seen through it — wood, cardboard, metal.

Chapter 6 · Concept 6 of 8

Soluble and Insoluble Materials

• Soluble — Completely dissolves in water — sugar, salt. Even some gases, like oxygen, are soluble in water — vital for aquatic life.
• Insoluble — Does not dissolve in water — sand, chalk powder, sawdust.

Chapter 6 · Concept 7 of 8

Mass and Volume

• Mass — The property that tells whether an object is heavier or lighter. A heavier object has more mass. Commonly measured using a balance.
• Volume — The amount of space occupied by an object or substance — shown by different water levels in identical tumblers.

Chapter 6 · Concept 8 of 8

What Is Matter?

• Mass and volume are two properties possessed by all materials.
• Matter — Anything that occupies space and has mass is called matter — mass is measured in grams (g) or kilograms (kg); volume in litres (L) or millilitres (mL).
• An ancient idea too — Ayurveda classified matter using 20 properties (guna) in 10 opposite pairs — like heavy/light and hot/cold.

Quick Recap

Check Your Understanding

1. 1Visit your kitchen and observe how your parents have organised various edibles. Can you suggest a better sorting method?
2. 2Unscramble the letters and match with their properties: (i) T R E M A T (ii) U L S B E L O (iii) T N E R P A S N A R T (iv) E R U S T L
3. 3Containers used to store materials in shops and homes are usually transparent. Why?