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What are the causes of mass wasting?

Many natural events cause mass wasting, including earthquakes, ice wedging and animal activity. During an earthquake, seismic waves shake unstable slopes, causing loose rock particles and soil to move. Ice wedging refers to the formation of ice crystals in the tiny crevices between rocks. When the water freezes, it expands, putting additional force on the rocks. Some of the rocks may wedge apart and fall from canyons, mountains or other slopes. As animals move across a slope, their activity may cause loose rocks to fall.\n\nAnother natural cause of mass wasting is the presence of excess water ..

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What are alkali metals used for?

Potassium is a component of KCl, which is a salt that people who need low-sodium diets may use as an alternative to table salt, NaCl. The element's yellow pigmentation makes potassium useful in making items such as dyes and fireworks. Lithium and rubidium are two additional alkali metals that are useful in the production of fireworks and other pyrotechnics. This is because when lithium salts are burned, an intense red color results, while burning rubidium produces a purple color. Lithium is also useful in making the rechargeable lithium-ion batteries that power many electronic devices. So..

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How does hydroelectricity work?

Hydroelectricity starts with a river that is flowing from an upland source through a valley that can contain a lake once the dam is built. The higher the elevation change, the greater the potential hydroelectric power that can be generated. Once the dam is built and the lake is filled, the hydroelectric dam can begin operation. Water is directed through channels in the dams past electric turbines. The turbines spin magnets inside generators which in turn generate electricity.\nWater stored in the lake has tremendous potential energy. This potential energy is converted to kinetic energy by the ..

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Why do people sneeze twice?

Sneezing happens when something irritates the nose or throat's mucous membranes. Sneezing helps humans eject harmful substances from their noses and mouths. Some people are genetically predisposed to sneeze at the sight of a bright light. This condition is called the photic sneeze reflex. Snatiation is a term for sneezing after a heavy meal.The most common cause for people to sneeze is catching a cold or being ill with a flu. People with allergies sneeze to expel dust, pollen, mold and animal dander. Certain nose sprays, which contain corticosteroids, can also cause sneezing. Polluted air..

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What is a purple velvet plant?

The purple velvet plant is native to Java and can only thrive outdoors in hardiness zones 10 to 12. It grows between 1 to 2 feet tall and has a spread of around 2 to 4 feet. The plant needs bright light but not direct sunlight. It also requires a moderate amount of watering that tapers off during the fall and winter months. The soil needs to be peaty and must be kept moist. If the soil dries out, the plant wilts.\nThe plant may also benefit from application of a diluted liquid fertilizer every fortnight during the growing season. As with watering, fertilizing needs to be cut back during the wi..

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What is human ventilation?

The human respiratory system consists of a tube leading from the nose and mouth down to two lungs. The lungs have millions of specialized cells called alveoli. These cells filter oxygen from the rest of the gas breathed in for providing directly to the blood. This is possible because of the tiny blood vessels called capillaries that surround the alveoli.\nBreathing is controlled by the expansion and contraction of the diaphragm. This dome-shaped muscle is located below the lungs, and it compresses and expands the lungs to make the body perform the subconscious reflex of breathing. The diaphrag..

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How are islands formed?

Volcanic islands are created as tectonic plates move over a lava flow. The lava flows up and cools, gradually building on itself to create islands that eventually break the surface of the ocean. The Hawaiian islands are a result of this process.\nContinental drift is when continents break apart; a process that occurs over many hundreds of thousands or millions of years. This creates strings of islands between landmasses and along the edges of landmasses.\nErosion also creates islands. The strip of land connecting the lower portion of a peninsula to a land mass can erode, turning the peninsula ..

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What are the elements of steel alloy?

Steel contains between 0.002 percent and 2.1 percent carbon with varying amounts categorizing the quality of the steel. Low carbon in the alloy produces a malleable alloy while high amounts of carbon result in a hard, brittle alloy commonly referred to as pig iron. Steel alloys can also be modified by adding small quantities of manganese, nickel, phosphorous, sulfur and several other elements. Small traces of oxygen, nitrogen and aluminum are also common.If the alloy is cast with more than 2.1 percent carbon, it is considered cast iron. Similarly, steel differs from wrought iron in the large a..

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What causes magma to rise to Earth's surface?

Magma is comprised of a mixture of molten rock, dissolved gases and crystals. Temperatures can range between 1300 and 2400 degrees Fahrenheit depending upon the type of magma. There are three general magma types: basaltic, andesitic and rhyolitic. The three magma types reflect their chemical composition. The gases dissolved in magma are primarily water vapor with some carbon dioxide and minor amounts of chlorine, sulfur and fluorine gases. Rhyolitic magma tends to contain a greater amount of gas than basaltic or andesitic magma. The gases present in magma expand in relation to the decrease in ..

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What are some examples of a stroichometry problem?

Chemical reactions are often written as equations in chemistry, where the reactants appear on the left side of the equation, and the products appear on the right side. The following is a simple chemical equation:\n2Na(s) + HCl(aq) ? 2NaCl(aq) + H2(g)\nA chemical equation displays the ions, molecules and atoms of all the substances involved in the equation.\nIn chemistry, chemical equations are balanced through the stoichiometric coefficients. When a chemical equation is balanced, it means that both sides have an equal number of elements. A stoichiometric coefficient is the number that appears ..

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