Grade 7
  1. Introduction to Physics  1.1. Definition and scope of physics  1.2. Importance of Physics in Daily Life and Technology  1.3. Scientific method and its applications in physics  1.4. Measurement and Experiments in Physics  1.5. Branches of Physics and their Applications  1.6. Relation of physics with other sciences
  2. Measurement and units  2.1. Fundamental and derived quantities  2.2. SI units and unit conversions  2.3. Length measuring instruments and tools used  2.4. Measuring the difference between mass and weight  2.5. Measuring time with accuracy  2.6. Measuring the Volume of Regular and Irregular Objects  2.7. Measuring Temperature and Temperature Scales  2.8. Accuracy, Precision, and Significant Figures  2.9. Errors in Measurement and How to Reduce Them  2.10. Estimates and approximations in scientific calculations  2.11. Standard form and order of magnitude
  3. Speed and Force  3.1. Introduction to motion and rest  3.2. Types of motion - uniform and non-uniform  3.3. Scalars and vectors in motion  3.4. Speed, Velocity, and Acceleration  3.5. Distance-time and velocity-time graphs  3.6. Newton's first law of motion (law of inertia)  3.7. Newton's second law of motion (force and acceleration)  3.8. newton's third law of motion  3.9. Types of forces - contact and non-contact forces  3.10. Effect of forces on motion  3.11. Friction – types, effects and applications  3.12. Gravity, free fall and gravitational acceleration  3.13. Circular motion and centripetal force  3.14. Application of Newton's laws in real life
  4. Energy, Work and Power  4.1. Definition and forms of energy  4.2. Potential and Kinetic Energy  4.3. Law of conservation of energy  4.4. Energy transformations in everyday life  4.5. Work done by force and its calculation  4.6. Power - Definition and Calculation  4.7. Simple Machines and Mechanical Advantage  4.8. Efficiency and energy losses of machines  4.9. Renewable and non-renewable energy sources
  5. Heat and temperature  5.1. Difference Between Heat and Temperature  5.2. Thermometer and temperature scale (Celsius, Kelvin, Fahrenheit)  5.3. Expansion and contraction of solids, liquids and gases  5.4. Heat transfer methods – conduction, convection and radiation  5.5. good and bad conductors of heat  5.6. Applications of heat transfer in daily life  5.7. Specific heat capacity and its applications  5.8. Latent heat and change of state  5.9. Thermal equilibrium and heat exchange  5.10. effect of heat on matter
  6. Lighting and Optics  6.1. Nature and properties of light  6.2. Reflection of light and laws of reflection  6.3. Image formation by plane and curved mirrors  6.4. Refraction of light and the laws of refraction  6.5. Lenses – convex and concave, image formation  6.6. Optical instruments – microscope, telescope, camera  6.7. Dispersion of light and formation of spectrum  6.8. Human eye, vision defects and their correction  6.9. Applications of optics in daily life  6.10. Total internal reflection and its applications
  7. Sound and waves  7.1. Nature and properties of waves  7.2. Production and propagation of sound  7.3. Characteristics of sound waves – frequency, amplitude, wavelength  7.4. Speed of sound in different mediums  7.5. Reflection of sound – echo and reverberation  7.6. Ultrasound and its applications  7.7. Doppler effect in sound waves  7.8. Noise pollution and its effects  7.9. Applications of sound in medicine and industry
  8. Electricity and Magnetism  8.1. Electric charge and static electricity  8.2. Electrical conductors and insulators  8.3. Electric current, voltage and resistance  8.4. Ohm's law and its applications  8.5. Electrical Circuits - Series and Parallel Circuits  8.6. Electric power and energy consumption  8.7. Safety precautions in the use of electricity  8.8. Properties of magnets and magnetic fields  8.9. Electromagnets - How They Work and Their Uses  8.10. Relation between electricity and magnetism (electromagnetic induction)  8.11. Applications of electromagnetism in technology  8.12. Earth's magnetic field and its effects
  9. Matter and its properties  9.1. Classification of matter- solid, liquid and gas  9.2. Properties of different states of matter  9.3. Kinetic theory of matter  9.4. Changes in the state of matter and their causes  9.5. Expansion and contraction of substances  9.6. Density and its calculation  9.7. Pressure in solids, liquids and gases  9.8. Atmospheric pressure and its effects  9.9. Applications of pressure in daily life  9.10. Buoyancy and Archimedes' principle
  10. Space Science and Solar System  10.1. Introduction to Astronomy  10.2. Solar System - Planets and their Characteristics  10.3. Sun - structure and energy production  10.4. Moon - phases and its effect on Earth  10.5. Rotation and revolution of the earth  10.6. Solar and lunar eclipses  10.7. Gravity in space and its role in orbits  10.8. Artificial satellites and their uses  10.9. Space exploration and modern discoveries  10.10. Asteroids, comets and meteors  10.11. Life beyond Earth - Possibilities and Theories
  11. Environmental Physics  11.1. Impact of physics on environmental science  11.2. Renewable and non-renewable energy sources  11.3. Energy conservation and efficiency  11.4. Climate change and its effects on Earth  11.5. Air, water and soil pollution – causes and effects  11.6. Greenhouse effect and global warming  11.7. Sustainable development and environmental protection  11.8. Role of Physics in Weather and Climate Studies

Grade 7 → Environmental Physics ↓


Air, water and soil pollution – causes and effects


Environmental pollution is a serious issue that affects our planet and everything living on it. Here we focus on three important types of pollution: air, water and soil pollution. These forms of pollution arise from various human activities and natural phenomena, adversely affecting our environment.

As we take a deeper look at each type, we'll explore what causes these problems and how they affect our health and the environment. Understanding these concepts is important for finding ways to reduce pollution and improve the health of the planet.

Air pollution

What is air pollution?

Air pollution means that there are harmful substances in the air we breathe. These substances can be natural, such as volcanic ash, or man-made, such as emissions from vehicles.

Causes of air pollution

  • Vehicle emissions: Cars, trucks and planes emit carbon monoxide, nitrogen oxides, hydrocarbons and particulates, which contribute significantly to air pollution.
  • Industrial emissions: Factories release a number of pollutants, including sulfur dioxide, carbon dioxide, and particulate matter.
  • Burning fossil fuels: The combustion of coal, oil, and gas for energy releases significant air pollutants, including greenhouse gases and particulate matter.
  • Natural sources: Wildfires, dust storms and volcanic eruptions can also contaminate the air.

Effects of air pollution

  • Health problems: Air pollution can cause respiratory diseases, heart problems and worsen existing health conditions such as asthma.
  • Environmental effects: Air pollutants can cause acid rain, which harms plants, soil and aquatic organisms.
  • Climate change: Greenhouse gases trap heat in the atmosphere, contributing to global warming and climate change.

Visual example of air pollution sources

traffic Industry Fossil fuels Nature

Water pollution

What is water pollution?

Water pollution occurs when harmful substances enter water bodies such as rivers, lakes, and oceans, making it unsafe for drinking, cooking, swimming, and other uses.

Causes of water pollution

  • Industrial waste: Many industries release pollutants directly into water bodies without treatment.
  • Sewage and wastewater: Untreated or poorly treated sewage contributes to water pollution.
  • Agricultural runoff: Pesticides and fertilizers run off into lakes and rivers, polluting them.
  • Marine Dumping: Dumping of plastic, garbage and toxic substances into the sea is a major cause of water pollution.

Effects of water pollution

  • Harm to aquatic life: Polluted water can cause death of aquatic life and disruption of the ecosystem.
  • Health hazards: Contaminated water can cause diseases like cholera and dysentery in humans.
  • Eutrophication: Excess nutrients in water bodies lead to algae blooms, which depletes oxygen and kills fish and other marine life.

Visual example of the water pollution cycle

Lake factory Agriculture

Soil pollution

What is soil pollution?

Soil pollution refers to the presence of toxic chemicals (pollutants or contaminants) in the soil, which have a negative impact on plant and animal life.

Causes of soil pollution

  • Industrial activity: Factories and industrial processes release chemicals, which can contaminate soil.
  • Pesticides and Fertilizers: Excessive use of these chemicals in agriculture pollutes the soil.
  • Deforestation: This removes the top layer of soil, leading to soil erosion and pollution.
  • Waste Disposal: Dumping non-biodegradable and toxic waste directly into the soil causes pollution.

Effects of soil pollution

  • Decrease in soil fertility: Pollutants destroy beneficial soil microorganisms, thereby reducing the quality of the soil.
  • Contamination of crops: Polluted soil can cause toxins to accumulate in crops, affecting food safety.
  • Water pollution: Contaminated soil can leach pollutants into groundwater, affecting water quality.

Visual example of the effects of soil pollution

Healthy Crop Polluted Crop factory

Conclusion

Pollution in air, water and soil is a significant challenge that requires urgent attention. Each type of pollution has different sources and adverse effects on health and the environment. However, it is possible to reduce pollution through clean technologies, better waste management practices and policies that encourage conservation and sustainability.

By understanding the causes and effects of air, water and soil pollution, we can take meaningful steps to reduce their impact and ensure a healthier and cleaner environment.


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Air, water and soil pollution – causes and effects

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