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What is fire made of?

Fire comes from the reaction between oxygen in the atmosphere and a fuel, such as wood or gasoline. When the fuel comes into contact with oxygen and is heated to its ignition point, fire is made. A typical wood fire is created from heating wood to a high temperature with something like a match, focused light, friction, lightning or material that is already burning. When the wood heats, some of it decomposes, and it is released as volatile gases or smoke. The rest of the material is made up of char, which is carbon and ash, a mix all of the minerals in the wood that cannot be burnt.\nWhen the v..

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Why is a stigma sticky?

Sometimes, the stigma, a surface located at the top of a flower's pistil, also traps pollen using hairs, flaps and other specially designed surfaces. Depending on the type of flower, stigmas vary in shapes and sizes. While some stigmas are long and thin, others feature round shapes and feathered or stringy borders. The stigma connects to the ovary though the style, a part of the flower that resembles a long tube.

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What causes a sink hole?

Natural sinkholes typically occur as a result of corroded underground water that develops long before the sinkhole appears. The sinkhole gradually develops as water slowly seeps in between the mud, rocks and minerals in the ground. The water erodes the rocks and minerals as it makes its way to ground water reservoirs. Sometimes, the water flow increases rapidly and washes away the underground structure. When the ground structure becomes too weak to support the surface of the earth, the ground collapses and forms a sinkhole. Natural sinkholes are bound to occur and cannot be prevented.\nHuman a..

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How long can a person survive without food?

In 1981, Bobby Sands dies after 66 days of a hunger strike. Other stories have emerged of stranded hikers surviving upwards of 50 to 60 days. Without food, the body succumbs to hunger and starts to eat away at muscle tissue and fat for energy. Some bodies are able to do this more efficiently than others, which explains the huge gap in how long a person can survive without eating.

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On what date did Isaac Newton discover gravity?

Between the summer of 1665 and July 5, 1687, there is record of Isaac Newton's communication with other scientists regarding laws of gravitation. He made three important discoveries during the summer of 1665 while Trinity College was shut down because of the plague. These discoveries included calculus, the components of white light, and theories of motion and gravity.\nAccording to Newton himself, he observed an apple falling from a tree while he was drinking tea. He realized that the same force which caused the apple to fall also caused the moon to orbit the earth.

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What is the smallest organ in the human body?

Melatonin in the only hormone that is secreted by the pineal gland. Controlled by light, its function is suppressed during the daytime yet increased at night as we prepare for sleep. The full purpose of the pineal gland has yet to be understood. In the past, the pineal gland was believed to be "the third eye" because of its regulation by light. It was once regarded as the "seat of the soul, where all thoughts are formed," according to the philosopher Descartes, but this claim has long since been rejected.

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What are some examples of a nucleophile vs. an electrophile?

Nucleophiles are molecules or ions that donate electrons. This is why the ammonia molecule NH3 is a nucleophile. The nitrogen ion in the molecule has a lone pair of electrons that are not tied up in any covalent bonds. As a result, these types of electrons can be donated to form a new bond with another atom. Negatively charged ions are nucleophiles because the electrons that give the ion a negative charge can easily combine with another atom or molecule to form a covalent bond. The other term for a nucleophile is a Lewis base, which is helpful when considering acid-base reactions.\nElectrophil..

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What is a cleavage fracture in minerals?

Many types of cleavage exists. Basal cleavage occurs in minerals that can be peeled off in sheets. Mica exhibits basal cleavage. Small cubes break off in cubic cleavage. Octrahedral cleavage is exhibited when wedges peel off a mineral.\nMinerals that fracture have chipped, uneven breaks in the rock. Some minerals that exhibit cleavage can fracture if chipped a certain way. It's possible to identify minerals by examining areas of stress for cleavage and fracture.

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How do you make a tornado for a science project?

Collect your materialsFind and clean two 2-liter plastic bottles. Remove any labels or debris that makes it harder to see inside the bottles. You also need duct tape, a pen or another tool of that size to create a hole, a pair of scissors and water.\nPrepare the first bottleCut a piece of duct tape large enough to cover securely the opening of one bottle. Puncture a hole in the center of the duct tape. Place the duct tape over one opening, and then use more tape around the side of the bottle opening.Fill the second bottleAdd water until the second bottle is three-quarters full. Do not place an..

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What is the minimum speed of hurricane winds?

The wind speeds incurred during a Category 1 hurricane are powerful enough to damage exterior structures on houses and other buildings, fell branches from trees, uproot smaller trees and damage power lines. A Category 2 hurricane has sustained winds of 96 to 110 miles per hour, and the winds of a Category 3 range from 111 to 129 miles per hour. A Category 4 hurricane has winds from 130 to 156 miles per hour, and the most catastrophic hurricane, a Category 5, has winds of 157 miles per hour or greater.

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