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Is N2O safe?

Nitrous oxide was originally synthesized in 1772 by Joseph Priestley. Humphry Davy discovered the pain-relieving property of the gas in 1800, but its use as a dental analgesic did not begin until 1844. Modern dentistry usually uses a mixture of 30 percent nitrous oxide and 70 percent oxygen. Signs of oversedation with nitrous oxide include nausea, sleepiness and flashbacks.

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How long is a strand of DNA when unwound?

The basic unit of DNA packaging in eukaryotic cells is a nucleosome, which consists of a DNA segment wrapped in sequence around eight histone protein cores. The nucleosomes are folded through a series of higher order structures, which eventually form a chromosome. Human cells are diploid, and have 22 different types of autosomal chromosomes presenting as two copies. Each cell also contains two sex chromosomes. In nearly every human cell, the approximately 6 feet of DNA is segmented throughout this 46 chromosome total.

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What is an electron cloud?

Previously, atoms were thought to be like miniature solar systems, with the nucleus acting as the star and electrons orbiting as planets. However, the Heisenberg Uncertainty Principle states that it is impossible to know both the exact location and velocity of an elementary particle; it is only possible to measure either one or the other. This is because electrons are so small that any particles used that interact them cause them to change velocity via physical collision. Velocity refers to both the speed and direction of movement, not just the speed, so the effect would be similar to a billia..

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Why do droughts happen?

While weather tends to follow patterns and cycles, the causes of these patterns can become disrupted over time. The Gulf Stream, for example, carries warm water near the equator north, where it warms up the western portion of the European continent. If the Gulf Stream stopped flowing, parts of England and other areas might receive less rain, which could cause droughts.\nDroughts are more common than many people imagine, and there are always droughts occurring in the United States. Over the years, experts have learned which areas are most vulnerable to drought, and they have prepared infrastruc..

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What are the causes of litter pollution?

To prevent litter pollution, waste reduction and proper disposal are important. Educating people about the effects of pollution and providing easy and appropriate means for litter disposal is important for proper disposal. Litter like broken glass, bottles and food wrappers from land find their way into waterways via stormwater systems, affecting marine life negatively. Waste can be reduced by practicing the three Rs, Recycle, Reduce, Reuse, in daily life. For example, recycling paper, metal, rechargeable batteries and plastics and purchasing recyclable products for use. Opting for reusable pr..

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What is a substance that conducts electricity under certain conditions?

Semiconductors' electrical conductivity increases with increasing temperatures. There are two basic classification of semiconductors, intrinsic and extrinsic semiconductors. Intrinsic semiconductors are group 14 elements that are able to form crystal lattice structures composed of atoms of that element, and are naturally occurring. Extrinsic semiconductors are not naturally occurring, they are artificially doped. This means they have impurities added to create additional electrons to the lattice so that they allow increased conduction.

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How do waves affect the shoreline?

Shorelines are affected by oscillation waves, which produce beach drifts and transport sand along the shore. Oscillation waves are formed by frictional drags of wind over the ocean's surface. The water particles in the waves move in near-circular orbits. The diameter of these orbits does not change, leading to a slowing down of the waves' speed as they approach shore. This churns up sand from the seafloor, eventually forcing waves to break.\nWhen waves break at an angle, they become translation waves. Translation waves are made of water particles moving forward. These waves hit the b..

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Does sodium chloride conduct electricity?

When melted or dissolved in water, however, the crystal lattice breaks down and allows the charged particles to move freely. This, in turn, allows the conduction of electricity. In order for any substance to be an electrical conductor particles must be charged, and those particles must be free to move to either the cathode or anode. As sodium chloride contains charged particles, only the state of the chemical matters when considering its ability to conduct electricity.

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What is a dissecting pin used for?

When placed properly through a specimen, dissection pins keep the specimen from moving during the cutting and examination. This allows for precise incisions that are necessary when dissecting small specimens. With full-body specimens, the pins are also used to hold skin and other tissue out of the way and to allow access to the internal organs of the specimen.

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What is p equals mv?

Momentum is inertia in motion, and inertia is determined by mass and measures the resistance of a body to changes in motion. Momentum is mass times velocity. A stationary object has some inertia, but its momentum is zero. The standard metric units for momentum are kilogram-meters per second. Momentum is also a vector quantity, meaning that it has both a magnitude and a direction.

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