Lesson 3 Study Notes
Lesson 3: Proper Use and Handling of Materials at Home and in School
Overview of Materials
Definition of Material/Substance: Refers to what things are made from.
Types of Materials:
Solids
Liquids
Gases
Effects on Living Beings: Certain substances have beneficial effects on humans, plants, and animals, while others can be harmful.
Substances in Daily Life
Usage Locations: Substances are found in:
Food
Home
Schools
Industries
Utility vs. Harm: Most materials are beneficial but can be harmful if misused.
Classification and Safety of Materials
Common Materials Found at Home:
Liquid Detergents: Used for cleaning.
Kitchen Utensils: Safe handling required.
LPG (Liquefied Petroleum Gas): Used for cooking, hazardous if not managed properly.
Uses and Characteristics of Materials
Metals:
Description: Solid, shiny, strong, malleable.
Applications: Tools, construction, jewelry, utensils, electric wires, doorknobs, surgical instruments.
Common Examples: Iron, copper, gold, silver.
Rubber:
Description: Stretchable material.
Uses: Erasers, rubber bands, tires.
Interactive Example: Stretching a rubber band to observe its flexibility.
Plastic:
Characteristics: Durable, waterproof, variety of properties (some transparent, some tough).
Uses: Bottles, bags, toys, novelty items.
Environmental Impact: Does not decompose easily, produces poisonous gases when burned.
Wood:
Source: Derived from trees, varies in density and strength.
Uses: Common in furniture due to its durability.
Environmental Responsibility: Importance of sustainable use of trees.
Other Uses of Materials
Fertilizers, Pesticides, and Detergents:
Fertilizers: Enhance soil fertility.
Pesticides: Target harmful insects; caution required to avoid toxicity.
Cleaning Detergents: Used for sanitation and hygiene.
Vitamins and Medicines:
Importance in health maintenance.
Example: Paracetamol for headache and fever relief.
Potential Harmfulness of Materials
Cleaning Detergents:
Hazards: Can lead to serious health issues if ingested or mismanaged.
Environmental Impact: Can be deadly to aquatic life when introduced into water sources.
Agricultural Chemicals:
Risks: Improper use can poison land, water, and living organisms, including humans.
Fossil Fuels:
Use: Powers vehicles.
Emissions: Carbon monoxide and nitrogen oxide are harmful pollutants affecting health.
Precautionary Measures in Handling Substances
Safety Practices:
Store hazardous chemicals out of reach of children; use protective gear when handling.
Keep flammable materials (e.g., gasoline, kerosene) at a safe distance from heat sources.
Secure vitamins and medicines in a locked cabinet; follow dosage guidelines and responsibly discard expired items.
Designate specific areas for different materials; label them properly to avoid confusion.
Dispose of hazardous materials correctly and avoid burning plastics to prevent air pollution.
Proper Disposal of Used Materials
Waste Segregation: Importance of proper waste management to prevent environmental harm.
Keep separate containers for wet and dry waste.
Clean and rinse recyclables before disposal.
Regularly dispose of waste following community guidelines.
Disposing of Used Oil:
Store used cooking oil in sealable containers; never mix it with regular household waste.
Reusing Materials:
Non-biodegradable materials (plastics, cans) can often be reused, e.g., using plastic bags multiple times, repurposing containers.
Recycling:
Definition: The process of remaking used materials into new products.
Items suitable for recycling: Paper, plastic, glass.
Benefit: Reduces waste and promotes a cleaner environment.
Conclusion and Key Takeaways
Technology and Chemicals: Modern advancements have led to both significant utility and potential harm in the materials we use.
Health and Environmental Connection: Understanding pollutants and proper safety practices enhances well-being and environmental health.