Science for Grade 7
1 Introduction to Science
1-1 Definition of Science
1-2 Importance of Science in Daily Life
1-3 Scientific Method
1-3 1 Observation
1-3 2 Hypothesis
1-3 3 Experimentation
1-3 4 Analysis
1-3 5 Conclusion
2 Matter and Its Properties
2-1 States of Matter
2-1 1 Solid
2-1 2 Liquid
2-1 3 Gas
2-2 Properties of Matter
2-2 1 Mass
2-2 2 Volume
2-2 3 Density
2-2 4 Solubility
2-3 Changes in Matter
2-3 1 Physical Changes
2-3 2 Chemical Changes
2-4 Mixtures and Solutions
2-4 1 Types of Mixtures
2-4 2 Separation Techniques
3 Force and Motion
3-1 Types of Forces
3-1 1 Gravitational Force
3-1 2 Frictional Force
3-1 3 Magnetic Force
3-1 4 Electrostatic Force
3-2 Motion
3-2 1 Speed and Velocity
3-2 2 Acceleration
3-2 3 Newton's Laws of Motion
3-2 3-1 First Law (Inertia)
3-2 3-2 Second Law (Force and Acceleration)
3-2 3-3 Third Law (Action and Reaction)
4 Energy
4-1 Forms of Energy
4-1 1 Kinetic Energy
4-1 2 Potential Energy
4-1 3 Thermal Energy
4-1 4 Electrical Energy
4-1 5 Light Energy
4-1 6 Sound Energy
4-2 Energy Conversion
4-2 1 Mechanical to Electrical
4-2 2 Chemical to Thermal
4-2 3 Light to Electrical
4-3 Conservation of Energy
5 Heat and Temperature
5-1 Temperature
5-1 1 Measurement of Temperature
5-1 2 Temperature Scales
5-2 Heat Transfer
5-2 1 Conduction
5-2 2 Convection
5-2 3 Radiation
5-3 Effects of Heat
5-3 1 Expansion
5-3 2 Change of State
6 Light and Sound
6-1 Light
6-1 1 Sources of Light
6-1 2 Reflection
6-1 3 Refraction
6-1 4 Lenses and Mirrors
6-2 Sound
6-2 1 Production of Sound
6-2 2 Properties of Sound
6-2 3 Reflection of Sound
6-2 4 Applications of Sound
7 Earth and Space
7-1 Earth's Structure
7-1 1 Crust
7-1 2 Mantle
7-1 3 Core
7-2 Earth's Atmosphere
7-2 1 Layers of the Atmosphere
7-2 2 Weather and Climate
7-3 Solar System
7-3 1 Planets
7-3 2 Sun
7-3 3 Moon
7-4 Space Exploration
7-4 1 Rockets
7-4 2 Satellites
7-4 3 Space Stations
8 Living Organisms and Ecosystems
8-1 Classification of Living Organisms
8-1 1 Kingdoms
8-1 2 Species
8-2 Ecosystems
8-2 1 Components of an Ecosystem
8-2 2 Food Chains and Webs
8-3 Adaptations
8-3 1 Physical Adaptations
8-3 2 Behavioral Adaptations
8-4 Human Impact on Ecosystems
8-4 1 Pollution
8-4 2 Conservation Efforts
9 Health and Nutrition
9-1 Human Body Systems
9-1 1 Circulatory System
9-1 2 Respiratory System
9-1 3 Digestive System
9-1 4 Nervous System
9-2 Nutrition
9-2 1 Essential Nutrients
9-2 2 Balanced Diet
9-3 Diseases and Prevention
9-3 1 Infectious Diseases
9-3 2 Non-infectious Diseases
9-3 3 Hygiene and Prevention
10 Environmental Science
10-1 Natural Resources
10-1 1 Renewable Resources
10-1 2 Non-renewable Resources
10-2 Pollution
10-2 1 Air Pollution
10-2 2 Water Pollution
10-2 3 Soil Pollution
10-3 Sustainable Development
10-3 1 Importance of Sustainability
10-3 2 Sustainable Practices
10-4 Climate Change
10-4 1 Causes of Climate Change
10-4 2 Effects of Climate Change
10-4 3 Mitigation Strategies
10.1.1 Renewable Resources Explained

Understanding Renewable Resources

Key Concepts

1. Definition of Renewable Resources

Renewable resources are natural resources that can be replenished or regenerated over a relatively short period of time. They are sustainable and do not deplete with use.

2. Types of Renewable Resources

Renewable resources include solar energy, wind energy, hydropower, geothermal energy, and biomass.

3. Solar Energy

Solar energy is derived from the sun's radiation and can be converted into electricity using solar panels.

4. Wind Energy

Wind energy is harnessed using wind turbines that convert the kinetic energy of wind into electrical energy.

5. Hydropower

Hydropower is generated by the movement of water, typically through dams, which drives turbines to produce electricity.

6. Geothermal Energy

Geothermal energy is heat from the Earth's interior, which can be used to generate electricity or provide heating and cooling.

7. Biomass

Biomass is organic material derived from plants and animals, which can be burned to produce energy or converted into biofuels.

8. Sustainability

Renewable resources are sustainable because they can be replenished naturally, ensuring a continuous supply of energy without depletion.

9. Environmental Impact

Renewable resources generally have a lower environmental impact compared to non-renewable resources, as they produce fewer greenhouse gases and pollutants.

10. Economic Benefits

Investing in renewable resources can create jobs, reduce dependence on imported fuels, and stimulate economic growth in local communities.

Explanation of Each Concept

1. Definition of Renewable Resources

Renewable resources are natural resources that can be replenished or regenerated over a relatively short period of time. Unlike non-renewable resources, such as fossil fuels, renewable resources do not deplete with use.

2. Types of Renewable Resources

Renewable resources include solar energy, wind energy, hydropower, geothermal energy, and biomass. Each type harnesses a different natural source to generate energy.

3. Solar Energy

Solar energy is derived from the sun's radiation. Solar panels convert sunlight into electricity through a process called the photovoltaic effect. This energy can be used to power homes, businesses, and even entire communities.

4. Wind Energy

Wind energy is harnessed using wind turbines. These turbines have blades that rotate in the wind, driving a generator to produce electricity. Wind farms can be located on land or offshore, capturing the kinetic energy of the wind.

5. Hydropower

Hydropower is generated by the movement of water. Dams are built to control the flow of water, which then drives turbines to produce electricity. Hydropower is one of the oldest and most reliable sources of renewable energy.

6. Geothermal Energy

Geothermal energy is heat from the Earth's interior. This heat can be used to generate electricity by pumping water into hot rocks and using the steam to drive turbines. Geothermal energy can also be used for heating and cooling buildings.

7. Biomass

Biomass is organic material derived from plants and animals. It can be burned directly to produce heat or converted into biofuels, such as ethanol and biodiesel. Biomass is a versatile renewable resource that can be used in various applications.

8. Sustainability

Renewable resources are sustainable because they can be replenished naturally. For example, the sun will continue to shine, and the wind will continue to blow, ensuring a continuous supply of energy without depletion.

9. Environmental Impact

Renewable resources generally have a lower environmental impact compared to non-renewable resources. They produce fewer greenhouse gases and pollutants, helping to mitigate climate change and reduce air and water pollution.

10. Economic Benefits

Investing in renewable resources can create jobs in manufacturing, installation, and maintenance. It can also reduce dependence on imported fuels, stimulate economic growth in local communities, and provide long-term energy security.

Examples and Analogies

Example 1: Solar Energy

Think of solar energy as a giant battery that the Earth carries. The sun constantly charges this battery with energy, which we can tap into using solar panels to power our homes and devices.

Example 2: Wind Energy

Wind energy can be compared to a windmill in a field. Just as a windmill harnesses the wind to grind grain, wind turbines harness the wind to generate electricity for our use.

Analogy: Renewable Resources as a Garden

Think of renewable resources as a garden that you can keep planting and harvesting. Each time you harvest, you plant new seeds, ensuring that the garden continues to produce. Similarly, renewable resources are constantly replenished, ensuring a continuous supply of energy.