📘 Chapter 6 – Sorting Materials into Groups

🔹 6.1 Observing Objects Around Us

1️⃣ Objects are made of different materials like paper 📄, wood 🌳, cloth 👕, glass 🪟, metal ⚙️, plastic 🧴, clay 🏺.
2️⃣ We can observe objects by their shape 🎨, feel ✋, and weight ⚖️.
3️⃣ Material → The substance used to make an object.

🔹 6.2 How to Group Materials?

✅ Grouping = putting objects into groups based on properties.
• By shape: Round ⚽ (ball, marble), Flat 📒 (book, ruler).
• By colour 🎨: Shiny 🌟 (spoon, keys), Dull 🪨 (stone, pot).
• By hardness: Hard 🪨 (stone, iron), Soft ☁️ (cotton, eraser).
• By material: Metal ⚙️, Plastic 🧴, Paper 📄, Clay 🏺.

Tip: One object can be made of different materials, and one material can be used for many objects.

🔹 6.3 Properties of Materials

✨ 6.3.1 Appearance

Lustrous (shiny ✨): Gold, Copper, Iron
Non-lustrous (dull 🚫): Paper, Wood, Rubber

🪨 6.3.2 Hardness

Hard 🪨: Stone, Iron, Wood
Soft ☁️: Cotton, Sponge, Pillow

👀 6.3.3 Transparency

Transparent: Glass, Water
Translucent: Frosted glass, Butter paper
Opaque: Wood, Cardboard

💧 6.3.4 Solubility

Soluble ✅: Sugar, Salt
Insoluble ❌: Sand, Sawdust
Liquids: Vinegar (soluble), Honey (slow soluble), Oil (insoluble)
Gases: Oxygen dissolves in water → helps fish live

⚖️ 6.3.5 Mass

More mass = heavier
Less mass = lighter

🥛 6.3.6 Volume

All objects occupy space.
Volume = space taken by matter.
Example: A 500 mL bottle can hold only 500 mL of water.

🔹 6.4 What is Matter?

✅ Matter = Anything that has mass and occupies space.
Mass → measured in grams (g), kilograms (kg).
Volume → measured in litres (L), millilitres (mL), cubic metre (m³).
🧪 Examples: Stone, Water, Air, Clothes, Fruits, Buildings.

🔹 Classification of Materials

We group materials based on similarities and differences.
Helps in studying, organising, and comparing.
Example:
• Kitchen 🍲 → utensils together
• Grocery 🛒 → spices separate from pulses
• Chemist shop 💊 → medicines in groups

🔹 The Invention of Plastic – Boon or Bane?

🌟 Boon: Cheap, strong, light, waterproof, useful in bottles, toys, bags.
⚠️ Bane: Causes pollution, harms animals, does not decay, burning releases harmful gases.
💡 Plastic is useful if recycled ♻️ and used wisely.

✅ Key Learning

• All materials are matter.
• Matter has mass and volume.
• Materials can be grouped and classified by their properties.
• This helps us study, understand, and use them better.