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
7.4.3 Space Stations Explained

Understanding Space Stations

Key Concepts

1. Definition of a Space Station

A space station is a large, habitable structure in space designed for human occupancy. It serves as a research laboratory, observatory, and living quarters for astronauts.

2. International Space Station (ISS)

The International Space Station is a collaborative project involving multiple countries, including the United States, Russia, Japan, Canada, and several European countries. It is the largest and most complex space station ever built.

3. Functionalities of a Space Station

Space stations perform various functions, including scientific research, technology development, and testing of systems for long-duration space travel.

4. Life Support Systems

Space stations are equipped with life support systems that provide astronauts with oxygen, water, food, and waste management. These systems are crucial for maintaining a habitable environment.

5. Scientific Experiments

Space stations host a wide range of scientific experiments, including studies on human physiology, materials science, biology, and Earth observation. These experiments help advance our understanding of space and Earth.

6. Orbital Mechanics

Space stations orbit the Earth in a specific path called an orbit. The altitude and inclination of the orbit are carefully calculated to ensure the station remains in a stable position relative to Earth.

7. Future Space Stations

Future space stations are being planned, including lunar and Martian habitats. These stations aim to support human exploration and colonization of other celestial bodies.

Explanation of Each Concept

1. Definition of a Space Station

A space station is a large, artificial structure designed to support human life and scientific research in space. It provides a stable environment for long-term stays and is equipped with all the necessary facilities for living and working.

2. International Space Station (ISS)

The International Space Station is the largest and most expensive space station ever built. It orbits Earth at an altitude of about 400 kilometers and has been continuously occupied since 2000. The ISS serves as a microgravity and space environment research laboratory.

3. Functionalities of a Space Station

Space stations are multifunctional. They conduct scientific research in fields such as biology, physics, astronomy, and meteorology. They also test technologies for future space missions and provide a platform for Earth observation.

4. Life Support Systems

Life support systems on space stations include oxygen generation, water recycling, food supply, and waste management. These systems ensure that astronauts can live and work in space for extended periods without resupply from Earth.

5. Scientific Experiments

Space stations host a variety of experiments that cannot be conducted on Earth due to gravity. These include studies on the effects of microgravity on the human body, the growth of crystals, and the behavior of fluids in space.

6. Orbital Mechanics

Space stations orbit the Earth in a path that keeps them at a constant distance from the planet. The orbit is determined by the station's altitude and inclination. The ISS orbits Earth every 90 minutes, experiencing 16 sunrises and sunsets each day.

7. Future Space Stations

Future space stations are being designed to support human missions to the Moon and Mars. These stations will provide habitats for astronauts, research facilities, and launch and landing sites for spacecraft.

Examples and Analogies

Example 1: Life Support Systems

Think of the life support systems on a space station as a mini ecosystem. Just as a forest recycles air and water, the space station recycles oxygen and water to sustain its inhabitants.

Example 2: Scientific Experiments

Imagine conducting an experiment in your kitchen, but without gravity. You could study how liquids behave differently, or how plants grow without the pull of Earth's gravity. This is similar to the experiments conducted on space stations.

Analogy: Space Station as a Floating City

Think of a space station as a floating city in the sky. Just like a city on Earth, it has homes, workplaces, and essential services. However, instead of being on the ground, it floats in space, providing a unique environment for its residents.