Grade 7
  1. Introduction to Chemistry  1.1. What is Chemistry?  1.2. Importance of chemistry in daily life  1.3. Branches of chemistry  1.4. Scientific Method in Chemistry  1.5. Laboratory Safety Rules and Precautions  1.6. Common Laboratory Equipment and Their Uses  1.7. Units of measurement in chemistry
  2. Matter and its properties  2.1. Definition of Matter  2.2. Classification of matter  2.3. Properties of matter  2.3.1. Physical properties  2.3.2. Chemical properties  2.4. States of matter  2.4.1. Solid state  2.4.2. Fluid state  2.4.3. Gaseous state  2.4.4. Plasma and Bose–Einstein condensates  2.5. Changes in the states of matter  2.5.1. Melting and freezing  2.5.2. Evaporation and Condensation  2.5.3. Sublimation and deposition  2.6. Density and its applications  2.7. Diffusion and its importance
  3. Elements, Compounds, and Mixtures  3.1. Definition of the element  3.2. Classification of elements  3.3. Metals, Nonmetals and Metalloids  3.4. Noble gases and their properties  3.5. Introduction to the Periodic Table  3.6. Definition of Compound  3.7. Properties of Compounds  3.8. Introduction to Chemical Formulas  3.9. Definition of Mixture  3.10. Types of mixtures  3.10.1. Homogeneous mixture  3.10.2. Heterogeneous mixtures  3.11. Difference Between Compounds and Mixtures  3.12. Solutions, Colloids and Suspensions
  4. Separation of mixtures  4.1. Need for separation of mixtures  4.2. Separation methods  4.2.1. Filtration  4.2.2. Sedimentation and decantation  4.2.3. Evaporation  4.2.4. Crystallization  4.2.5. Distillation  4.2.6. Chromatography  4.2.7. Magnetic Separation  4.2.8. Centrifugation
  5. Atomic Structure  5.1. Introduction to Atoms  5.2. Structure of the atom  5.2.1. Nucleus and electron cloud  5.3. Subatomic particles  5.3.1. Proton  5.3.2. Neutron  5.3.3. Electrons  5.4. Atomic number and mass number  5.5. Isotopes and their uses  5.6. Ions and ion formation
  6. Periodic table  6.1. Introduction to the Periodic Table  6.2. Groups and periods  6.3. Trends in the Periodic Table  6.3.1. Atomic Size  6.3.2. Metallic and non-metallic character  6.3.3. Electronegativity  6.3.4. Reactivity of the elements  6.4. Alkali metals and their properties
  7. Chemical bond  7.1. Why do atoms form bonds?  7.2. Types of chemical bonds  7.2.1. Ionic bond  7.2.2. Covalent bond  7.2.3. Metal Bond  7.3. Properties of Ionic and Covalent Compounds  7.4. Intermolecular forces
  8. Chemical reactions  8.1. Introduction to Chemical Reactions  8.2. Signs of a chemical reaction  8.3. Types of Chemical Reactions  8.3.1. Combination Reactions  8.3.2. Decomposition reactions  8.3.3. Displacement reactions  8.3.4. Double displacement reactions  8.3.5. Combustion reactions  8.4. Law of conservation of mass  8.5. Balancing simple chemical equations
  9. Acids, Bases and Salts  9.1. Definition of Acid and Base  9.2. Properties of Acids  9.3. Properties of bases  9.4. pH Scale and Indicators  9.5. Neutralization reactions  9.6. Common Acids and Bases in Everyday Life  9.7. Preparation and use of salts  9.8. Strong and weak acids and bases
  10. Solutions and Solubility  10.1. Definition of Solution  10.2. Components of the solution  10.2.1. Solvent  10.2.2. solute  10.3. Factors Affecting Solubility  10.4. Concentration of solutions  10.5. Saturated and unsaturated solutions  10.6. Colloids and suspensions  10.7. Solubility curve and its interpretation
  11. Air and atmosphere  11.1. Composition of air  11.2. Properties of gases in the air  11.3. Importance of Oxygen and Carbon Dioxide  11.4. Air pollution and its effects  11.5. Greenhouse effect and global warming  11.6. Ways to reduce air pollution  11.7. Ozone layer and its importance
  12. Water and its importance  12.1. Properties of Water  12.2. Water as the universal solvent  12.3. Importance of water for life  12.4. Water pollution and its effects  12.5. Water Purification  12.5.1. Filtration  12.5.2. boil  12.5.3. Chlorination in water purification  12.5.4. reverse osmosis  12.6. Hard and soft water  12.7. Water cycle and its importance
  13. Fuel and energy  13.1. Types of fuel  13.1.1. Fossil fuels  13.1.2. Renewable energy sources  13.2. Combustion and energy release  13.3. Global warming and its effects  13.4. Alternative sources of energy  13.5. Ways to conserve energy
  14. Metals and Nonmetals  14.1. Physical and chemical properties of metals  14.2. Physical and Chemical Properties of Non-Metals  14.3. Difference Between Metals and Nonmetals  14.4. Uses of metals and nonmetals  14.5. Corrosion of metals and its prevention  14.6. Alloys and their importance
  15. Plastics and polymers  15.1. Natural and synthetic polymers  15.2. Properties of plastics  15.3. Biodegradable and Non-Biodegradable Plastics  15.4. Environmental impact of plastic  15.5. Recycling and waste management in plastics and polymers  15.6. Daily Uses of Polymers
  16. Introduction to Organic Chemistry  16.1. Basic definitions of organic chemistry  16.2. Carbon Compounds in Daily Life  16.3. Hydrocarbons  16.4. Simple functional groups (alcohols and carboxylic acids)  16.5. Importance of organic compounds in industry

Grade 7 → Plastics and polymers ↓


Environmental impact of plastic


Plastics are a type of material that we use in everyday life. They are everywhere, from water bottles and food packaging to toys and electronics. While plastics are incredibly useful, they can also harm our environment. In this lesson, we will explore how plastics affect the environment and what we can do to reduce these impacts.

What are plastics?

Plastics are materials made from polymers. Polymers are long chains of molecules that can be molded into different shapes. They are made by linking together smaller units called monomers. The unique structure of polymers gives plastics certain properties, such as being lightweight, strong, and flexible.

Polymer: A large molecule made of many repeating units (monomers).

Here is a simple example of how monomers form a polymer.

Monomer Monomer Monomer Monomer Polymer

Examples of polymers include plastic materials such as polyethylene, polypropylene, and polystyrene. Each type of plastic has its own monomer and use.

Problems related to plastic

Although plastic is useful, it also brings many environmental problems.

1. Non-biodegradable

Most plastics do not decompose naturally like food or plants. This means that they remain in the environment for hundreds of years. This characteristic makes waste management very challenging.

Example: A plastic bottle can take up to 450 years to decompose in a landfill.

2. Pollution

Plastic pollution is one of the biggest environmental challenges. It affects both land and water environments.

Plastic in the ocean Plastic on the ground Plastic in the air

Plastic waste can be found in our oceans, which harms marine life. Animals may mistake plastic for food and eat it, which can cause injury or death.

Example: Sea turtles eat plastic bags, mistaking them for jellyfish (their favorite food).

3. Harm to wildlife

Plastic waste is dangerous for animals. Animals can become entangled in plastic debris or ingest it, which can lead to suffocation, injury, or death.

4. Chemicals

Plastic often contains harmful chemicals. These chemicals can leach into the environment and enter the food chain, affecting human and animal health.

BPA (Bisphenol A): A chemical used to make certain plastics that can leach into food and drinks.

5. Microplastics

Microplastics are tiny plastic particles smaller than 5mm in size. They can come from larger plastic debris that breaks down over time or from products such as cosmetics and cleaning agents. These tiny plastics are difficult to clean up and can accumulate in the food chain.

Example: Microbeads in facial scrubs are tiny plastic particles that end up in the ocean and are consumed by marine animals.

Solution to the plastic problem

Now let's look at some ways in which we can reduce the negative impact of plastic on the environment.

1. Reduce, Reuse, Recycle

The 3 R’s (Reduce, Reuse, Recycle) are important in managing plastic waste.

  • Reduce: Use less plastic products.
  • Reuse: Reuse plastic items instead of throwing them away.
  • Recycling: Recycle plastic products to make new products.

Recycling involves collecting used plastics and reprocessing them to make new materials. This process helps reduce the amount of new plastic produced.

2. Biodegradable plastic

Scientists are developing biodegradable plastics that can break down in the environment more quickly than regular plastics.

Biodegradable Plastics: Plastics designed to break down more quickly in the environment.

Although it is not a perfect solution, biodegradable plastic can help reduce the impact of plastic waste.

3. Alternatives to plastic

Using alternative materials can help reduce reliance on plastic. These materials include glass, paper or metal, which are often more environmentally friendly.

4. Clean-up efforts

Many organizations and volunteers work to clean up plastic waste from natural areas, especially beaches and oceans. These efforts can help improve habitats and remove plastic debris from key ecosystems.

Conclusion

Plastic is an important part of our daily lives, but it also creates environmental challenges. By understanding the impact of plastic and taking steps to reduce these impacts, we can help protect our planet. The combined efforts of individuals, communities and governments around the world are vital to address the problems caused by plastic waste.

There is no single solution to the plastic problem, but through concerted and informed efforts we can make a difference to the natural world.


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Environmental impact of plastic

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