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When was boron discovered?

Boron was discovered by combining potassium and boric acid. Its name comes from the Persian word "Burah" and the Arabic word "Buraq," both of which mean 'borax." When heated, boron gives off a green color, making it a desirable element for pyrotechnics. The compound borax is a common ingredient in laundry detergents and antiseptics.\nBoron has an atomic number of five, atomic weight of 10.811 and atomic symbol of B. In its standard state, it is a solid that is classified as a semi-metal.

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What is the human body made up of?

The composition of the different elements within the body plays a role in the formation if different types of bodily materials, such as fats, protein and DNA. About.com explains that water, composed of two hydrogen atoms and a single oxygen atom, primarily derives its mass from the heavy oxygen molecule. This explains how the human body can simultaneously be mostly water and most densely oxygen. The human body, like all organic compounds, contains a significant amount of carbon. Oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus are the elements that make up 99 percent of the human bod..

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What is the color of Polaris?

A star's classification is based on its temperature, which is often determined by its elemental composition. An F7 star is near the lower end of the temperature scale for class F stars, nearer to the cooler, yellow class G stars than the hotter, white class A stars. Scientists determine the color of stars by calculating their spectral wavelength. Measurements of their mass, radius and luminosity are also taken as these factors also influence their color.

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What are the functions of an NPN transistor?

An NPN transistor is composed of semiconductor material with three terminals for connecting with an external circuit. The three terminals are named the collector, the base and the emitter. The collector terminal is normally connected to a positive electric supply and the emitter to a negative electric supply. Both NPN and PNP transistors are the same in their function but have opposite current flows. For any given state of operation, the voltage polarities and current directions for each kind of transistor are exactly opposite to each other. In an NPN transistor, current flows from the collect..

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What is the function of pericycle?

Pericycle is classified as a primary tissue, which means that it plays an essential role in keeping plants alive. This tissue is located proximately to the root systems of plants and trees: on diagrams, it appears as the peripheral (outermost) layer of vascular root cylinders. Although pericycle is located below the ground, out of sight of growing and flowering plants, it plays a key role in enabling plant growth. Pericycle, in this capacity, functions much like the stage crew in a theater performance: while the tissue never makes an appearance, it stays hard at work to make sure all parts of ..

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What is a theodolite?

Theodolites are commonly used for surveying and triangulation in road building, tunnel alignment and other civil engineering projects. They come in several varieties suited to different types of projects. A transit theodolite is built so that it can completely reverse directions. A phototheolodite is equipped with a camera, and is commonly used in map making.

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What is an encephalization quotient?

The formula for an encephalization quotient does not take into account different individual weights. Instead, the formula assumes an average weight for the entire species. Otherwise, a human that weighs 300 pounds would have a different EQ than one who weighs 150 pounds. The formula also does not account for neuron density, cortical thickness or other structures of the brain. The EQ serves as a general way to externally measure intelligence.\nAnimals that have higher enchephalization quotients are smarter than those with lower figures. In general, mammals and birds have higher EQ figures than ..

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What is an eukaryotic cell?

Eukaryotic cells probably developed around 2 billion years ago. Scientists believe the first eukaryotes were some form of algae. These cells make up every advanced form of earthly life, from mosses and fungus to the human body. Unlike prokaryotic bacteria and even simpler viruses, eukaryotic cells are "factories" of life, with organelles that function to provide cellular energy, eliminate toxins, create proteins and reproduce. By specializing these tasks, the eukaryotic cell was able to function more efficiently than primitive prokaryotes, giving it an evolutionary edge and enabling it to form..

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When was the first hurricane?

Hurricanes are tropical cyclones occurring in the North Atlantic and Northeast Pacific Oceans; similar storms in the Northwest Pacific are called typhoons. All tropical cyclones are large storm systems featuring strong winds and thunderstorms spiraling around strong low-pressure centers. Hurricanes cause major property damage and loss of human life but may help regulate regional and global climates by carrying heat from tropical regions to temperate zones.

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How many vertebrae does a human being have?

The vertebrae support most of the weight the spine receives. A bony projection on each side of a vertebra supports the arch that protects the spinal canal.\n\n\n\nSeven vertebrae form the neck and make up the cervical spine. The upper back has 12 vertebrae that are collectively known as the thoracic spine. The lower back has five vertebrae and is called the lumbar spine. It is the area of the spine that bears the most weight. The sacrum and coccyx are home to the nine vertebrae that fuse together by adulthood to form a solid unit.

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