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 → Fuel and energy ↓


Global warming and its effects


Introduction to global warming

Global warming is the gradual increase in the average temperature of the Earth's surface. It is caused primarily by the increase of greenhouse gases such as carbon dioxide (CO 2), methane (CH 4), and nitrous oxide (N 2 O) in the atmosphere. These gases trap heat from the sun, preventing it from escaping back into space—a phenomenon known as the "greenhouse effect."

The science behind global warming

When sunlight reaches Earth, it is either absorbed by the surface or reflected back into space. Gases such as CO 2 and CH 4 in the atmosphere capture and trap some of this heat. This process is essential for life on Earth because without it, our planet would be too cold for most species to survive.

However, human activities, especially the burning of fossil fuels such as coal, oil and natural gas, increase the amount of greenhouse gases in the atmosphere. As a result, more heat is trapped, raising the Earth's temperature.

The role of fossil fuels

Fossil fuels are formed from the remains of ancient plants and animals. Over millions of years, heat and pressure transformed these organic materials into coal, oil, and natural gas. When fossil fuels are burned, a significant amount of CO 2 is released, which is a major contributor to global warming.

Example: Combustion of methane

CH 4 + 2O 2 → CO 2 + 2H 2 O

This reaction shows how methane, when burned, combines with oxygen (O 2) in the air to form carbon dioxide (CO 2) and water (H 2 O).

Effects of global warming

Rising sea levels

As the Earth's temperature rises, polar ice caps and glaciers melt, causing sea levels to rise. Coastal areas are particularly at risk of flooding.

Example: If a glacier containing 1,000 cubic kilometers of ice melts, it could significantly raise global sea levels, threatening cities located near the coast.

Seasonal changes

Global warming is causing weather events such as storms, droughts and heatwaves to become more frequent and severe. CO 2 plays a major role in these changes.

Effects on the ecosystem

Many animal species are affected because their habitats change or disappear. For example, polar bears are struggling because the Arctic ice is melting, reducing their hunting grounds.

Effects on humans

Global warming affects agriculture, water supply, and health. Higher temperatures can lead to heat-related illnesses, while changes in rainfall can lead to water shortages.

Steps to reduce global warming

Reducing fossil fuel use

One of the most effective ways to tackle global warming is to reduce our dependence on fossil fuels. This can be achieved by using renewable energy sources such as solar, wind and hydropower.

Increased energy efficiency

Improving energy efficiency in industries, transport and homes can reduce CO 2 emissions to a great extent. For example, using LED bulbs instead of traditional incandescent light bulbs saves energy.

Afforestation and reforestation

Planting trees absorbs CO 2 from the atmosphere. Trees use CO 2 for photosynthesis, which gives us oxygen and reduces atmospheric carbon.

Using public transportation

Encouraging the use of public transport and reducing the number of vehicles on the road can also help cut CO 2 emissions.

Conclusion

Global warming is one of the most serious issues facing our planet today. Its effects are widespread, affecting weather patterns, sea levels, ecosystems, and human life. However, there are measures we can take to reduce its effects by reducing greenhouse gas emissions and adopting sustainable practices. Everyone can contribute to this effort by being mindful of energy consumption, using renewable energy sources, and supporting policies aimed at reducing environmental impact.


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Global warming and its effects

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