📘 Materials of Daily Use (Science + Pedagogy)

🔹 1. Introduction

Everything we see and use around us is made of some material. Each material is chosen because it has special properties that make it suitable for that purpose. For example, copper wire is used in electricity because it is a good conductor, while plastic bottles are preferred for storage because they are light and non-reactive.

In teaching, the aim is not just to list materials but to let children observe, classify, compare and test them. This way, they learn by doing and not just by memorising.

🔹 2. Classification of Materials

(A) By Source

  • Natural Materials: Obtained from plants, animals or minerals. Example: Cotton (plant), Wool (sheep), Iron (mineral), Wood (tree).
  • Synthetic Materials: Made by humans in factories. Example: Nylon, Polyester, PVC, Bakelite.

(B) By Decomposition

  • Biodegradable: Can be broken down naturally. Example: Paper, Cotton, Jute bags.
  • Non-biodegradable: Do not decompose, cause pollution. Example: Plastic bottles, Glass bottles, Thermocol plates.

(C) By Properties

  • Metals: Iron, Copper, Aluminium.
  • Non-metals: Sulphur, Carbon (Graphite), Oxygen.
  • Conductors: Copper wire (allow current).
  • Insulators: Plastic, Rubber (stop current).
  • Transparent: Glass tumbler.
  • Translucent: Oiled paper.
  • Opaque: Wooden door.

🔹 3. Properties of Materials

  • Lustre: Metals like gold and silver shine, which is why they are used in jewellery. Non-metals like coal are dull.
  • Hardness: Iron and steel are hard and used in machines. Wax and rubber are soft and used in toys.
  • Malleability: Aluminium can be hammered into thin sheets like foil. Gold leaf is so thin it is used in decoration.
  • Ductility: Copper and aluminium can be stretched into wires, which is why they are used in electricity.
  • Elasticity: Rubber bands and nylon ropes stretch and return to their shape.
  • Conduction: Steel utensils get hot on flame (conductors). Plastic handles of pans stay cool (insulators).
  • Transparency: A glass window is transparent, frosted glass is translucent, and a wooden wall is opaque.
  • Heat Resistance: A steel cooker can withstand high heat, but plastic melts.
  • Density: An iron nail sinks in water, while a wooden stick floats.

🔹 4. Common Materials and Their Uses

Metals: Copper & aluminium (wires), Iron (machines, tools, bridges), Gold & silver (ornaments).

Non-Metals: Graphite (pencils, electrodes), Sulphur (fireworks, medicines).

Alloys: Brass (utensils, instruments), Bronze (statues, medals), Stainless steel (utensils, surgical tools).

Plastics: PVC & polythene (pipes, bottles), Bakelite (switches, handles), Teflon (non-stick pans), Melamine (fire-resistant utensils, uniforms).

Fibres:

  • Natural → Cotton (summer clothes), Wool (sweaters, blankets), Silk (sarees), Jute (bags, ropes).
  • Synthetic → Nylon (ropes, parachutes), Rayon (artificial silk), Polyester (durable clothes).

🔹 5. Changes in Materials

  • Physical Change: Only form or state changes, no new substance. Example: Melting ice, tearing paper, dissolving sugar.
  • Chemical Change: A new substance is formed. Example: Rusting of iron, burning paper, curdling milk.
  • Reversible: Melting wax, freezing water.
  • Irreversible: Burning wood, baking cake.

🔹 6. Environmental Issues

Materials like plastic and thermocol are non-biodegradable and cause serious pollution. Animals often die after eating polythene bags. To solve this, we must recycle glass, paper and metals and encourage the use of eco-friendly alternatives like cloth and jute bags. Teachers should also raise awareness about sustainable living.

🔹 7. Pedagogy of Teaching “Materials”

  • Observation: Students compare objects for shine, hardness, or transparency.
  • Experimentation: Students test conductivity with a battery-bulb setup or check solubility of salt vs chalk.
  • Demonstration: Teacher shows burning of magnesium ribbon or melting of plastic.
  • Case-based: Example – “Why is aluminium foil used to wrap food but not newspaper?”
  • Group Work: Students bring items like a spoon, cloth, wire, or bottle and classify them.
  • Constructivist approach: Students discover rules of classification by themselves.

Classroom Example: A teacher brings a steel spoon, a wooden scale and a copper wire. Students test them with a simple electric circuit. They observe that copper conducts electricity, while wood does not. This direct experience makes learning meaningful.

🔹 8. CTET/B.Ed Exam Key Points

  • Focus on properties and uses of metals, non-metals, plastics and fibres.
  • Differences between natural and synthetic fibres are frequently asked.
  • Alloys like brass, bronze and stainless steel are important examples.
  • Environmental issues of plastics are key pedagogy + EVS links.
  • Pedagogy should stress learning by doing, observation, classification and experiments.
  • As per NCF 2005 and NEP 2020, science must be hands-on, child-centred, and inquiry-based.

📊 Quick Revision Table

Property/Concept
Examples
Uses/Applications
Lustre
Gold, Silver
Jewellery
Hardness
Iron, Steel
Tools, machines
Softness
Wax, Rubber
Toys, modelling
Malleability
Aluminium, Gold
Foils, sheets
Ductility
Copper, Aluminium
Wires
Elasticity
Rubber band, Nylon rope
Elastic products, ropes
Conduction
Copper wire, Iron rod
Electric wiring, cookware
Insulation
Plastic handle, Rubber covering
Switches, utensil handles
Transparency
Glass window
Windows, spectacles
Translucent
Frosted glass, Oiled paper
Bathroom glass, lampshades
Opaque
Wooden door, Stone wall
Walls, furniture
Biodegradable
Cotton, Paper, Jute
Eco-friendly items
Non-biodegradable
Plastic, Glass, Thermocol
Persistent daily items
Alloy (Brass)
Copper + Zinc
Utensils, instruments
Alloy (Bronze)
Copper + Tin
Statues, medals, coins
Alloy (Stainless Steel)
Iron + Chromium + Nickel
Utensils, surgical tools
Natural Fibre
Cotton, Wool, Silk, Jute
Clothes, ropes, bags
Synthetic Fibre
Nylon, Rayon, Polyester
Ropes, fabrics, parachutes
Plastic (PVC/Polythene)
Pipes, bottles, carry bags
Packaging, storage
Bakelite
Switches, Plug boards
Electrical insulation
Teflon
Non-stick cookware
Frying pans
Melamine
Fire-resistant uniforms, Kitchenware
Safety, utensils

✅ Clean Laila font, size 11 throughout (including headings). Copy–paste ready for ctet.xyz.