Earth
The Earth is the third planet from the Sun and the only known planet to support life. It is a complex and dynamic system that is constantly changing and evolving. Let's explore some key aspects of the Earth:
Structure of the Earth
The Earth is made up of several layers:
- Crust: The outermost layer, where we live. It is made up of solid rock and is divided into tectonic plates.
- Mantle: The layer beneath the crust, composed of semi-solid rock that flows over long periods of time.
- Outer Core: A layer of molten iron and nickel that surrounds the inner core.
- Inner Core: The solid, dense center of the Earth, composed mostly of iron and nickel.
Geological Processes
The Earth is constantly undergoing geological processes that shape its surface:
- Plate Tectonics: The movement of tectonic plates, which can cause earthquakes, volcanic eruptions, and the formation of mountain ranges.
- Erosion: The wearing away of the Earth's surface by water, wind, and ice.
- Weathering: The breakdown of rocks and minerals on the Earth's surface.
Atmosphere
The Earth is surrounded by a layer of gases known as the atmosphere:
- Troposphere: The lowest layer where weather occurs and contains the air we breathe.
- Stratosphere: Contains the ozone layer, which protects the Earth from the sun's harmful ultraviolet radiation.
- Mesosphere: The middle layer that protects the Earth from meteoroids.
- Thermosphere: The outermost layer where the Northern and Southern Lights occur.
Hydrosphere
The Earth's water is contained in the hydrosphere:
- Oceans: The largest bodies of water on Earth, covering about 70% of the planet's surface.
- Rivers and Lakes: Freshwater sources that support various ecosystems and human activities.
- Water Cycle: The continuous movement of water between the Earth's surface and the atmosphere through processes like evaporation, condensation, and precipitation.
Conclusion
The Earth is a remarkable and unique planet that sustains life through its interconnected systems. Understanding its structure, processes, and components is crucial for understanding the world around us.
[Earth] Related Worksheets and Study Guides:
.◂Science Worksheets and Study Guides Fourth Grade. Organ systems
Study Guide
Organ systems 
Worksheet/Answer key
Organ systems Worksheet/Answer key
Organ systems Worksheet/Answer key
Organ systems Vocabulary/Answer key
Organ systems Vocabulary/Answer key
Organ systems Vocabulary/Answer key
Organ systems Vocabulary/Answer key
Organ systems Vocabulary/Answer key
Organ systems
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyVocabulary/Answer keyVocabulary/Answer keyVocabulary/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
LIFE SCIENCE (NGSS)
From Molecules to Organisms: Structures and Processes
Students who demonstrate understanding can:
Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.