Carbon Cycle

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Carbon Atom Noun

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[kar-buhn at-uhm]

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Carbon Atom

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The fundamental chemical element that is the basis of all known life, capable of forming a vast number of compounds.

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Example: This Bohr model diagram shows a carbon atom has a central nucleus with 6 protons and 6 neutrons, and 6 electrons orbiting in shells.

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Carbon Cycle Noun

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[kar-buhn sy-kuhl]

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Carbon Cycle

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The continuous process by which carbon atoms are exchanged among the atmosphere, biosphere, hydrosphere, and geosphere.

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Example: This diagram shows how carbon moves through Earth's systems. Plants take in carbon dioxide (CO2) for photosynthesis, while animals, roots, and factories release CO2.

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Atmosphere Noun

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[at-muhs-feer]

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Atmosphere

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The envelope of gases surrounding the Earth, which contains carbon primarily in the form of carbon dioxide.

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Example: This diagram shows Earth's atmosphere is a mix of gases, mostly nitrogen and oxygen, and includes a small amount of carbon dioxide.

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Biosphere Noun

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[bahy-oh-sfeer]

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Biosphere

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The global ecological system integrating all living beings and their relationships, including their role in carbon exchange.

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Example: This diagram shows the biosphere is the part of Earth where life exists, combining the atmosphere (air), lithosphere (land), and hydrosphere (water).

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Hydrosphere Noun

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[hahy-droh-sfeer]

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Hydrosphere

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All the waters on the earth's surface, such as lakes and seas, which can dissolve and store atmospheric carbon dioxide.

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Example: This diagram shows the hydrosphere (a body of water) absorbing carbon dioxide (CO2) from the atmosphere, demonstrating its role as a carbon sink in the carbon cycle.

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Geosphere Noun

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[jee-oh-sfeer]

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Geosphere

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The solid parts of the Earth, including rocks, soil, and sediments, where carbon is stored for long periods.

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Example: This diagram shows how tectonic plates move, causing volcanoes to form. Volcanoes release carbon stored in the Earth's geosphere into the atmosphere.

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Photosynthesis Noun

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[foh-toh-sin-thuh-sis]

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Photosynthesis

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The process used by plants to convert light energy into chemical energy by consuming carbon dioxide from the atmosphere.

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Example: A plant uses light energy from the sun to convert carbon dioxide and water into sugar (food), releasing oxygen as a byproduct.

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Diffusion Noun

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[dih-fyoo-zhuhn]

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Diffusion

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The net movement of molecules from an area of higher concentration to an area of lower concentration.

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Example: This image shows diffusion in the lungs, where carbon dioxide (CO2) moves from a high concentration in the blood to a low concentration in the alveoli.

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Carbon Sink Noun

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[kar-buhn singk]

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Carbon Sink

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A natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period.

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Example: This diagram shows a plant absorbing carbon dioxide from the air to make its food, which demonstrates how plants act as a natural carbon sink.

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Limestone Noun

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[lahym-stohn]

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Limestone

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A sedimentary rock composed primarily of calcium carbonate, formed from marine organism shells and acting as a carbon reservoir.

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Example: This limestone rock contains visible fossils, showing how carbon from ancient sea creatures is stored in the Earth's crust as part of the carbon cycle.