What Is Weather

Front

Atmosphere Noun

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[at-muh-sfeer]

Back

Atmosphere

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The envelope of gases that surrounds a celestial body, such as a planet or star, held in place by gravity.

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Example: The image shows Earth's atmosphere layers, each labeled, teaching how gases are organized around the planet.

Front

Air Noun

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[air]

Back

Air

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The invisible mixture of gases, primarily nitrogen and oxygen, that constitutes the Earth's atmosphere and is essential for life.

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Example: The image shows Earth's atmosphere composition: 78% nitrogen, 21% oxygen, and 1% other gases.

Front

Nitrogen Noun

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[nai-truh-juhn]

Back

Nitrogen

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A colorless, odorless, and unreactive gas that forms about 78 percent of the Earth's atmosphere.

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Example: This diagram shows that nitrogen makes up 78% of Earth's atmosphere, helping students understand its abundance in the air.

Front

Oxygen Noun

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[ok-si-juhn]

Back

Oxygen

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A reactive gas essential for respiration that makes up about 21 percent of the Earth's atmosphere.

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Example: The image shows Earth's atmosphere composition, highlighting oxygen's 21% presence, essential for respiration.

Front

Permanent Gas Noun

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[pur-muh-nuhnt gas]

Back

Permanent Gas

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An atmospheric gas, such as nitrogen or oxygen, whose concentration remains stable and constant over time.

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Example: The image shows Earth's atmosphere with nitrogen and oxygen as stable gases, explaining 'permanent gas' in weather context.

Front

Variable Gas Noun

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[vair-ee-uh-buhl gas]

Back

Variable Gas

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An atmospheric gas, such as water vapor, whose concentration fluctuates in response to environmental processes and activities.

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Example: Solar radiation interacts with variable gases like water vapor in the atmosphere, affecting weather.

Front

Water Vapor Noun

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[waw-ter vey-per]

Back

Water Vapor

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Water that is present in the atmosphere in its gaseous state, and is the most abundant variable gas.

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Example: Water vapor rises from the river, forms clouds, and falls as rain, showing the water cycle.

Front

Carbon Dioxide Noun

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[kar-buhn dai-ok-said]

Back

Carbon Dioxide

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A variable gas essential for photosynthesis and produced during respiration, playing a key role in Earth's carbon cycle.

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Example: The image shows carbon dioxide's role in the carbon cycle, including absorption by plants and release by animals and factories.

Front

Ozone Noun

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[oh-zohn]

Back

Ozone

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A reactive form of oxygen with three atoms (O3) that creates a protective layer in the stratosphere.

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Example: The ozone layer blocks harmful UV rays from the sun, protecting life on Earth.

Front

Methane Noun

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[meth-eyn]

Back

Methane

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A potent greenhouse gas that is the main component of natural gas and is produced by various natural processes.

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Example: Methane is a gas produced by cows that contributes to greenhouse gases.