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How much do humans sleep in a lifetime?

LiveScience states that as of 2006, 25 percent of Americans use some form of sleeping aid at night. The number of adults aged 20 to 44 that reported using sleeping pills also doubled from 2000 to 2004. A six-year study conducted by the University of California, San Diego of more than 1 million adults showed that people who get only six to seven hours of sleep a night have a lower death rate than those who get a full eight hours of sleep.

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What are some ways to view a launch at Wallops Island?

The Wallops Visitor Center is about 4 miles from the launch pads, and NASA recommends arriving at least 30 minutes before launch time. Arbuckle Neck in Assawoman is another spot that offers views of launches. It is about a mile away from Wallops Island. Wrights Restaurant, about 4 miles from Wallops Island, also provides a good view of launches.

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What are the key differences between solutions and mechanical mixtures?

A solution is a type of mixture. In general, mixtures combine substances that neither bond to one another nor experience chemical reactions. Also, a mixture’s substances can be added without regard to fixed ratios.\nA mechanical mixture is non-uniform, meaning that the distribution of each substance throughout the mixture is inconsistent, and its substances remain separate after they are added. Mehanical mixtures are also referred to as heterogeneous mixtures. Salt, sand and water are an example of a mechanical mixture.\nSolutions have the same concentration of substances throughout the mixt..

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What happens when an acid and a base are combined?

Mixing an acid and a base results in neutralization, but the results are potentially dangerous. No matter which acid or base is used, the resulting solution is water and varying types of salt. The process of neutralization often involves the substances heating up when they come together. If the solution heats up too much or too fast, a violent explosion or the creation of harmful or flammable gases is a possibility. This occurs when the chemicals are mixed too quickly, the acid and base are too strong or if there is no available salt to be made in the solution.\nA mild example of this is when ..

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Is water a polar molecule?

Polar molecules can possess a stronger positive or negative charge than the other charge, due to atoms not attracting each other with equal force. This results in molecules that can be completely nonpolar, or completely polar. Nonpolar molecules are those molecules with a polarity of zero, where electronegative charge is balanced throughout the molecule. Polar molecules have an unbalanced charge, resulting in a more positive or negative polar molecule. In essence, what determines a polar molecule is whether electrons are shared evenly between its components.\nSome examples of nonpolar molecule..

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Why do animals hibernate?

Hibernation and hibernation-like states take many forms in the animal kingdom. Some rodents, such as ground squirrels, enter periods of deep sleep during which their body temperatures drop to the temperature of the air around them and respiration and heart rate lower dramatically. These animals also wake for short periods during hibernation.\nThe body temperature of bears does not drop as significantly as that of rodents. Bears, however, can go for six months or more without waking, eating or drinking.\nHummingbirds enter a hibernation-like state, or torpor, each night. Hummingbirds consume up..

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How are volcanic arcs formed?

In North America, the volcanoes of the Cascade range, including Mount Shasta, Mount Ranier, Mount Hood and Mount Saint Helens, form a volcanic arc where the Jaun de Fuca Plate subducts under the North American Plate. The arc is nearly 700 miles long and extends from the Mendicino Triangle in Northern California into British Columbia.\nFarther north is the Aleutian Arc, formed by the subduction zone in the Aleutian Trench. The volcanic arc extends from Southeast Alaska 1,500 miles along the Aleutian Islands chain across the northern Pacific Ocean to the Kamchatka Peninsula of Russia. Over 100 v..

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What is the name of the ionic compound KOH?

KOH is a compound in which each molecule is made from one potassium ion and one hydroxide ion. It is formed by reacting impure potassium with sodium hydroxide. Like many ionic compounds, it is soluble in water and separates into its constituent K(+1) and OH(-1) ions in solution. This makes it a reactive base. The compound is hygroscopic, which means that it absorbs water easily. Because of this, it is used as a drying agent in laboratories.

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What are mixtures in science?

The two types of mixtures are heterogeneous mixtures and homogeneous mixtures. Homogeneous mixtures are uniform mixtures with components that are not easily distinguishable through simple observation. Components in a homogeneous mixture are not easily separated by mechanical means and are all in the same state of matter, meaning that a homogeneous mixture is composed of exclusively gas, liquid, or solid components. Examples of homogeneous mixtures include metal alloys, sugar water and vinegar.\nHeterogeneous mixtures contain components of a variety of shapes and sizes and are not uniform. The ..

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Why is carbon dioxide nonpolar?

The bonds in carbon dioxide are polar because carbon and oxygen have a difference in electronegativity of more than 0.4. Each bond has a dipole moment, which means that the electrons are not shared equally. In carbon dioxide, the oxygen atoms are more electronegative, so the electrons spend more time on the side with the oxygen atoms. The entire molecule is nonpolar because the bonds are linear, and the dipole moments point in opposite directions. This linear configuration cancels out the dipole moments, leaving a net polarity of zero.

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