Difference between revisions of "Carbon dioxide"
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| − | '''Carbon dioxide''' in an odorless, invisible gas formed by the combustion of | + | '''Carbon dioxide''' in an odorless, invisible [[gas]] formed by the [[combustion]] of [[hydrocarbon]]s, both nataurally, in the human body, and artificially, as fuel. It is one of the human body's major waste products, being excreted through exhalation. |
| − | It is used by plants in the process of [[photosynthesis]] to generate [[oxygen]]. | + | It is used by plants in the process of [[photosynthesis]] to generate [[oxygen]]. Plants use carbon dioxide in [[photosynthesis]]. |
At room temperature, it is a gas. It becomes solid at extremely cold temperatures, forming [[dry ice]]. When it thaws, it turns directly into a gas again (see [[sublimation]]). <ref>"Dry ice is frozen carbon dioxide. A block of dry ice has a surface temperature of -109.3 degrees Fahrenheit (-78.5 degrees C). Dry ice also has the very nice feature of sublimation -- as it breaks down, it turns directly into carbon dioxide gas rather than a liquid." [http://www.howstuffworks.com/question264.htm How Stuff Works] </ref> | At room temperature, it is a gas. It becomes solid at extremely cold temperatures, forming [[dry ice]]. When it thaws, it turns directly into a gas again (see [[sublimation]]). <ref>"Dry ice is frozen carbon dioxide. A block of dry ice has a surface temperature of -109.3 degrees Fahrenheit (-78.5 degrees C). Dry ice also has the very nice feature of sublimation -- as it breaks down, it turns directly into carbon dioxide gas rather than a liquid." [http://www.howstuffworks.com/question264.htm How Stuff Works] </ref> | ||
Revision as of 19:56, April 6, 2007
Carbon dioxide in an odorless, invisible gas formed by the combustion of hydrocarbons, both nataurally, in the human body, and artificially, as fuel. It is one of the human body's major waste products, being excreted through exhalation. It is used by plants in the process of photosynthesis to generate oxygen. Plants use carbon dioxide in photosynthesis.
At room temperature, it is a gas. It becomes solid at extremely cold temperatures, forming dry ice. When it thaws, it turns directly into a gas again (see sublimation). [1]
Each molecule of carbon dioxide has one carbon atom and two oxygen atoms, so its chemical formula is CO2.
CO2 is one of the so-called "greenhouse" gases. Heat-trapping by CO2 has been observed on Earth and Venus. The extent of its role in the current increase in average global temperatures is a topic of active political discussion.
- ↑ "Dry ice is frozen carbon dioxide. A block of dry ice has a surface temperature of -109.3 degrees Fahrenheit (-78.5 degrees C). Dry ice also has the very nice feature of sublimation -- as it breaks down, it turns directly into carbon dioxide gas rather than a liquid." How Stuff Works