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Chromium is the third hardest element after carbon and boron. Its Mohs hardness is 8.5, which means that it can scratch samples of quartz and topaz , but can be scratched by corundum . Chromium is highly resistant to tarnishing , which makes it useful as a metal that preserves its outermost layer from corroding , unlike other metals such as ...
The Pelton wheel or Pelton Turbine is an impulse -type water turbine invented by American inventor Lester Allan Pelton in the 1870s. [1] [2] The Pelton wheel extracts energy from the impulse of moving water, as opposed to water's dead weight like the traditional overshot water wheel. Many earlier variations of impulse turbines existed, but they ...
In electricity generation, a generator [1] is a device that converts motion-based power ( potential and kinetic energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even ...
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The pages in this category are redirects from The Wheel of Time fictional elements. To add a redirect to this category, place {{ Fictional element redirect |series_name=The Wheel of Time}} on the second new line (skip a line) after #REDIRECT [[Target page name]] .
List of chemical elements. 118 chemical elements have been identified and named officially by IUPAC. A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z ). [1]
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Classical elements. According to ancient and medieval science, aether ( / ˈiːθər /, alternative spellings include æther, aither, and ether ), also known as the fifth element or quintessence, is the material that fills the region of the universe beyond the terrestrial sphere. [1] The concept of aether was used in several theories to explain ...