... a relatively recent occurrence. North American French explorers knew of sources of native copper in the region of Lake Superior and the area natives had copper jewelry and ornamentation. Earnest copper mining began in Simsbury, Connecticut about 1709 and copper was actually exported to England after a source was discovered in New Jersey around 1719. In later times domestic copper resources did not satisfy national needs until the discovery of gold in California shifted the focus of mineral exploration westward and strikes of rich copper ores occurred in Tennessee and the Cordilleran base regions. The Civil War caused copper demand to increase greatly in or ...
... nylon, and an inner layer made of 100% cotton. It's the winter again and the weather is becoming colder. Each morning many people wonder what to wear to stay as warm as possible, but they aren't sure which material will keep them warmest. The experiment was chosen to see which clothing insulator retains the most heat. "Insulation is material that protects against heat, cold, electricity, or sound." (Science Encyclopedia, 1984). In this case the insulation will be protecting against a cold temperature. The hypothesis is if denim, cotton T-shirt material, wool fabric, polyester fabric, thermal underwear, and a Ziplock bag with out insulating material are tes ...
... Diocletian is said to have ordered all Egyptian works concerning the chemistry of gold and silver to be burned in order to stop such experiments. Zosimus the Theban (about AD 250-300) discovered that sulfuric acid is a solvent of metals, and he liberated oxygen from the red oxide of mercury. The fundamental concept of stemmed from the Aristotelian doctrine that all things tend to reach perfection. Because other metals were thought to be less "perfect" than gold, it was reasonable to assume that nature formed gold out of other metals deep within the earth and that with sufficient skill and diligence an artisan could duplicate this process in the workshop. Efforts t ...
... made either of clear plastic sheets, or of glass. The sun's rays go through the glass, and heat up the air inside the building, and they have a hard time getting out. These rays get trapped inside the building, and continually heat the air inside, and even through the night the rays stay in and heat the air. The greenhouse is also called a "HOT HOUSE" because it gets so hot. The greenhouse effect is caused by gases such as carbon monoxide, carbon dioxide, and nitrogen escaping into the atmosphere. These gases get trapped in the ozone layer and do not let the suns rays escape very easily. This causes the earth to warm up. This warming can cause droughts, an ...
... Often exceeds 30 m (100 ft) in length, and the smallest shrews, mice, and bats are often less than 5 cm (less than 2 in) in length. In many mammals the color of the skin or fur blends with the animal’s natural surroundings. In others there is great contrast with the natural surroundings to favorvisual signals that provide information about theidentity of a species, and about the gender, age, orsocial status of an individual. The skin also functions as a sensory and excretory organ and contains specialized glands. Mammary glands, which are present in fully developed form in all adult female mammals. Aquatic mammals, such as whales, dolphins, and sea ...
... process of muscular tissue by first injuring them, then the muscles heal quicker adding more fiber increasing their bulk. Many athletes turn to steroids more often because they're cheaper then marijuana or cocaine. A ten week cycle of testosterone cypinate and methandrostone costs only about one hundred dollars. Steroids are also very hard to trace because of their water base composition. They can pass through the body within two days. All these benefits of steroids help an athletes become more competitive and increase their chance of being a winner. Of course everybody wants better biceps and triceps but when using steroids to achieve this go ...
... in the ozone layer are forming over the polar regions and these are increasing in size annually. Paradoxically, ozone is toxic! Undiluted ozone is bluish in colour. Liquid ozone is bluish-black, and solid ozone is violet-black. Oxygen is very reactive and capable of combining with most elements. It is essential for respiration of all plants and animals and for practically all combustion. history of oxygen Leonardo da Vinci suggested that air consists of at least two different gases. Before then, air was felt to be an element in its own right. He was also aware that one of these gases supported both flames and life. Oxygen was prepared by several w ...
... may lose consciousness due to asphyxia (oxygen deprivation). During the exchange of gases in the normal breathing process, the blood stream absorbs oxygen from air in the lungs, while carbon dioxide passes from the blood to the air. When you hold your breath, the exchange of gases slows, as "stale" air in the lungs is no longer replaced by "fresh" air. Oxygen is actually removed from the blood stream during the exchange of gases. depending on how completely oxygen is replaced by helium, you may lose consciousness quickly and without warning - you may literally pass out while still standing. The usual result is an uncontrolled fall that can cause serious i ...
... odor, precipitate, or gas appear. Identification of an unknown substance is accomplished when a known one is found with identical properties. If none is found, the uknown substance must be a newly identified chemical. Tests should not use up excessive amounts of a material to be identified. Most chemical methods of qualitative analysis require a very small amount of the sample. Advance instrumental techniques often use less than one millionth of a gram. An example of this is mass spectrometry. Quantitative chemical analysis is used to determine the amounts of constituents. Most work in analytical chemistry is quantitative. It is also the most difficult. ...
... the animal kingdom. Estimates range from 1500 to 2200 different mantid species WORLDWIDE. The most common figure given, though, is about 1800. The ways the Mantid's are classified in the Animal Kingdom. There is agreement that the collection of mantid species make up the Mantidae family of insects. The Mantidae family, in turn, is part of the order/suborder Mantodea that includes a variety of mantid-like species. But the existing literature does not reflect a clear consensus about what insect order Mantodea belong in. Some have placed Mantodea in the Dictyoptera Order-with the roaches. Others place Mantodea in the Orthoptera Order-with crickets and grasshopper ...
