... used to create it. However because of the difficulty and cost of properly disposing of these products they are often emitted into the atmosphere with little or no treatment. The term was first considered to be important about 20 years ago when scientists in Sweden and Norway first believed that acidic rain may be causing great ecological damage to the planet. The problem was that by the time that the scientist found the problem it was already very large. Detecting an acid lake is often quite difficult. A lake does not become acid over night. It happens over a period of many years, some times decades. The changes a ...

... Alexander M. Prokhorov and Nikolai G. Basov, and the American Gordon Gould. But the first laser was constructed in 1960 by American physicist T.H. Maiman and it is still one of the most powerful available. This laser used a ruby rod for its active medium, which is its way of producing light. Ali Javan then created the first gas laser later in 1960. Three separate teams of American scientists operated the first semiconductor laser in 1962. Then in 1966, the American physicist Peter Sorokin built the first dye laser. To begin with, I will explain the definition of a laser: It is a device that produces a very narrow ...

... on Earth, but it is about 0.05 ppm at sea level. Ozone absorbs harmful ultraviolet radiation in the upper atmosphere, and protects humans from skin cancer. But ozone is also the main ingredient of smog, and causes serious health effects and forest and crop damage in the lower atmosphere. Ozone is formed through the chemical reaction of volatile organic compounds and nitrogen dioxide, in the atmosphere, in the presence of sunlight. This reaction is called a photochemical reaction, because sunlight is required. The product is known as smog. The notorious brownish color of smog is due to nitrogen dioxide of the mixt ...

... sun makes the earth's weather and climate, and heats the earth; in return. Greenhouse gases (water vapor, carbon dioxide, and other gases) trap some of the energy that leaves, botteling heat like the glass panels of a greenhouse. Without this natural "greenhouse effect," temperatures would be alot lower than they are now, and life like today would not work. Instead, thanks to greenhouse gases, the earth's average temperature is better, 60°F. But, problems may happen when the amount of greenhouse gases increases. Since the beginning of the industrial revolution, great amounts of carbon dioxid ...

... for magma that has been released onto the Earth's surface. When lava comes to the Earth's surface, it is red hot and may have temperatures of more than 2012 degrees Fahrenheit. Fluid lava flows swiftly down a volcano's slopes. Sticky lava flows more slowly. As the lava cools, it may harden into many different formations. Highly fluid lava hardens into smooth, folded sheets of rock called pahoehoe. Stickier lava cools into rough, jagged sheets of rock called aa. Pahoehoe and aa cover large areas of Hawaii, where the terms originated. The stickiest lava forms flows of boulders and rubble called block flows. It may als ...

... to perform an activity, they form a tissue. The cells of a human are organized into tissues such as muscle and nerve tissues. Plant tissues include those of the stem and root. Many cells in tissues are linked to each other at contact sites called cell junctions. Cell junctions help maintain differences in the internal environment between adjacent cells, help anchor cells together, and allow cells to communicate with one another by passing small molecules from one cell to another. Groups of two or more tissues that function together make up organs. An organ system is a group of organs that work together to carry ...

... of individual grains of loose sediment, such as gravel and sand. Chemical are formed by chemical precipitation from solution. These two categories are not exclusive because most clastic carry some chemical sediment, and most chemical also contain some loose sediment material. All are in general characterized by the parallel arrangement of their mineral layers or beds, which are distinguished from each other by differences in thickness, the size of the grains, or color. All rock disintegrate slowly as a result of mechanical weathering and chemical weathering. Mechanical weathering is the breakdown of rock int ...

... 29 protons/electrons (atomic number) and 35 neutrons. It's atomic weight is 65.39. Copper is an orangy, red metal that is found in ores as a solid form. It can be found in such countries as the United States, Chile, Zambia, Zaire, Peru, and Canada. The most important copper ores are the sulfides, oxides, and carbonates. From these copper is obtained by smelting, leaching, and electrolysis. It's alloys, brass and bronze, long used, are still very important; all American coins are now copper alloys; gun metals also contain copper. The most important compounds are the oxide and the sulfate, blue vitrol; co ...

... centigrade. The water that was in the reactor is instantly turned to steam which creates tremendous amount of pressure in the reactor core. Above the reactor core there is a 5 foot thick lead plate and above that there is a meter thick floor composed of iron, barium, serpentine, concrete, and stone. The exploding steam fires the floor up like shrapnel. The metal plate goes through the four foot thick concrete roof like butter and reaches and altitude of sixty meters. You can hear ripping, rending, wrenching, screeching, scraping, tearing sounds of a vast machine breaking apart. L. Ray Silver, a leading author wh ...

... of one chain and those of the other. An A is always bonded to a T, and every G is paired with a C; the result is that the sequence of bases in the two strands is complementary. The arrangement of the bases determines the genetic code of an organism. This code directs the synthesis of proteins at the cellular level. It is written in units called codons, each of which specifies a particular amino acid. (Proteins are composed of amino acids.) A codon consists of a sequence of three bases--for example, GAG or TCA. The four bases can be assembled into 64 possible codons. Because proteins are built from only 20 amino ...