When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Carbon cycle - Wikipedia

    en.wikipedia.org/wiki/Carbon_cycle

    The carbon cycle is a part of the biogeochemical cycle where carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of Earth.Other major biogeochemical cycles include the nitrogen cycle and the water cycle.

  3. Conservation of energy - Wikipedia

    en.wikipedia.org/wiki/Conservation_of_energy

    This is an accepted version of this page This is the latest accepted revision, reviewed on 6 February 2025. Law of physics and chemistry This article is about the law of conservation of energy in physics. For sustainable energy resources, see Energy conservation. Part of a series on Continuum mechanics J = − D d φ d x {\displaystyle J=-D{\frac {d\varphi }{dx}}} Fick's laws of diffusion Laws ...

  4. Valence and conduction bands - Wikipedia

    en.wikipedia.org/wiki/Valence_and_conduction_bands

    In solid-state physics, the valence band and conduction band are the bands closest to the Fermi level, and thus determine the electrical conductivity of the solid. In nonmetals, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature, while the conduction band is the lowest range of vacant electronic states.

  5. Carbon-based life - Wikipedia

    en.wikipedia.org/wiki/Carbon-based_life

    The carbon cycle is a biogeochemical cycle that is important in maintaining life on Earth over a long time span. The cycle includes carbon sequestration and carbon sinks . [ 4 ] [ 5 ] Plate tectonics are needed for life over a long time span, and carbon-based life is important in the plate tectonics process. [ 6 ]

  6. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...

  7. Energy flow (ecology) - Wikipedia

    en.wikipedia.org/wiki/Energy_flow_(ecology)

    The carbon cycle of a terrestrial ecosystem. [6] Beginning with photosynthesis, water (blue) and carbon dioxide (white) from the air are taken in with solar energy (yellow), and are converted into plant energy (green). [7] 100×10 15 grams of carbon/year fixed by photosynthetic organisms, which is equivalent to 4×10 18 kJ/yr = 4×10 21 J/yr of ...

  8. Chemical cycling - Wikipedia

    en.wikipedia.org/wiki/Chemical_cycling

    The majority of known chemical cycles on Venus involve its dense atmosphere and compounds of carbon and sulphur, the most significant being a strong carbon dioxide cycle. [3] The lack of a complete carbon cycle including a geochemical carbon cycle, for example, is thought to be a cause of its runaway greenhouse effect, due to the lack of a ...

  9. Convection (heat transfer) - Wikipedia

    en.wikipedia.org/wiki/Convection_(Heat_transfer)

    [3] In many real-life applications (e.g. heat losses at solar central receivers or cooling of photovoltaic panels), natural and forced convection occur at the same time (mixed convection). [4] Internal and external flow can also classify convection. Internal flow occurs when a fluid is enclosed by a solid boundary such as when flowing through a ...