unit three: matter, energy, and earth
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UNIT THREE: Matter, Energy, and Earth. Chapter 8 Matter and Temperature Chapter 9 Heat Chapter 10 Properties of Matter Chapter 11 Earth’s Atmosphere and Weather. Chapter Eleven: Earth’s Atmosphere and Weather. 11.1 Earth’s Atmosphere 11.2 Weather Variables - PowerPoint PPT PresentationTRANSCRIPT
UNIT THREE: Matter, Energy, and Earth
Chapter 8 Matter and Temperature
Chapter 9 HeatChapter 10 Properties of MatterChapter 11 Earth’s Atmosphere and Weather
Chapter Eleven: Earth’s Atmosphereand Weather
11.1 Earth’s Atmosphere11.2 Weather Variables11.3 Weather Patterns
Investigation 11A
Key Question: How does solar radiation affect the heating
and cooling of continents and oceans?
Heating Land and Water
11.1 Learning Goals
Describe the composition of Earth’s atmosphere.
Explain the meaning of atmospheric pressure and describe how it is measured.
Identify the layers of Earth’s atmosphere and discuss unique characteristics of each layer.
11.1 The Atmosphere Earth’s atmosphere is a
layer of gases surrounding the planet, protecting and sustaining life. It insulates us so that we
don’t freeze at night. Its ozone layer protects us
from the sun’s ultraviolet rays.
It also contains the carbon dioxide needed by plants for photosynthesis, and the oxygen we need to breathe.
11.1 What's in Earth's atmosphere? This wonderful protective layer exists around
Earth because our planet has just the right balance of size and distance from the sun.
Nitrogen gas makes up about 78 percent of Earth’s atmosphere.
The second most abundant gas is oxygen, which makes up 21 percent of Earth’s atmosphere.
11.1 Nitrogen Cycle Nitrogen is
important to protein which is found in the body tissues of all living things.
Nitrogen is cycled through the soil and into plants and finally when living things die and decay.
11.1 Why is Earth different? The atmospheres of Venus, Earth, and Mars
were formed in similar ways, so we might expect them to contain similar elements.
Photosynthesis changed Earth’s atmosphere.
Photosynthesis and the atmosphere
Photosynthesis converts carbon dioxide to oxygen in a process that allows living things use the sun’s energy.
11.1 Earth stores carbon
Many marine organisms such as microscopic phytoplankton use carbon dioxide dissolved in seawater to form shells of calcium carbonate.
11.1 Atmospheric
pressure Atmospheric pressure is a measurement of the force due to air molecules at a given altitude.
The pressure of the atmosphere decreases as you rise above sea level.
11.1 Pressure changes with altitude
11.1 Atmospheric pressure At sea level, the weight
of the column of air above a person is about 9,800 newtons (2,200 pounds)!
This is equal to the weight of a small car.
Why aren’t we crushed by this pressure?
11.1 Measuring Pressure
11.1 Measuring PressureA barometer is an instrument that measures atmospheric pressure.
Long ago, mercury barometers were used.
11.1 Parts of an Aneroid Barometer
11.1 Layers of the
AtmosphereFour Layers Thermosphere Mesosphere Stratosphere Troposphere*
11.1 Our Atmosphere1. Troposphere: where
we live2. Stratosphere:
contains the ozone layer
3. Mesosphere: where the temperature is coldest
4. Thermosphere, where the temperature is highest
Other layers The ionosphere is part
of the thermosphere and is where the Sun’s ultraviolet light creates charged atoms and molecules called ions.
The exosphere begins at about 500 kilometers above Earth’s surface and does not have a specific outer limit.