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Nonmetal Silicon

explanatory Essay
939 words
939 words
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Nonmetal Silicon The second most abundant element on Earth is the nonmetal

silicon, which makes up about 28 percent of the Earth's crust. It

occurs only in such combined forms as silica (silicon dioxide) and

silicate rocks and minerals. The most common form of silica is quartz,

which includes sand and flint. Silicates are salts in which silica is

combined with oxygen and other elements, such as aluminum, magnesium,

calcium, sodium, iron, and potassium.

Silicon has a strong affinity for oxygen. Pure silicon can be obtained

by breaking down its combined form. It is prepared commercially by

reducing (removing the oxygen from) the oxide by reaction with a

carbon-based substance such as coke in electric furnaces. Some silicon

is obtained by reducing silicon dioxide with aluminum. Amorphous

silicon, prepared in the laboratory by heating silica with magnesium

powder, is a dark-brown crystalline powder.

Pure silicon is a hard, dark-gray solid with a metallic luster. Its

crystalline structure is the same as that of the diamond form of

carbon, with which silicon shares many chemical and physical

properties. Elemental silicon has few applications; it is used in

metallurgy as a reducing agent and as an alloying element in steel,

brass, and bronze. (See also Alloy.)

Highly purified silicon is a poor conductor of electricity. When it is

doped, or treated with other atoms, however, it yields electrons for a

current. The silicon that is produced in this process is used

extensively in transistors, integrated circuits, photoelectric

devices, and othe...

... middle of paper ...

...20? C) 5.75-7.31

Boiling Point 4,118? F (2,270? C)

Melting Point 450? F (232? C)

Germanium, brittle silver element predicted in 1871 by Mendeleev but

not discovered until 1886 by Clemens Winkler. It is used as

superconductor in electronics; window and lens component in equipment

to measure infrared radiation; component of camera lenses and

microscopes; and in transistors and in phosphors for fluorescent

lamps. It is found as a part of the minerals argyrodite, germanite,

and renierite and in coal. It can kill certain harmful bacteria

without causing toxicity to humans and is being studied as a

therapeutic agent.

Properties of Germanium

Symbol Ge Atomic number 32 Atomic weight 72.59 Group in periodic table

IVa Boiling point 4,892o F (2,700o C) Melting point 1,719o F (937.2o

C) Specific gravity 5.323

In this essay, the author

  • Explains that the second most abundant element on earth is the nonmetal silicon, which makes up about 28 percent of the earth's crust. the most common form of silica is quartz.
  • Explains that silicon has a strong affinity for oxygen. pure silicon can be obtained by breaking down its combined form.
  • Explains that silicon, prepared in the laboratory by heating silica with magnesium powder, is a dark-brown crystalline powder.
  • Explains that highly purified silicon is a poor conductor of electricity and is used extensively in transistors, integrated circuits and photoelectric devices.
  • Explains that silicon valley is a region in california famous for computer technology because of the significance of silicon in microprocessors.
  • Explains that silicon aerogels are transparent, highly porous substances consisting of tiny spheres of bonded silicon and oxygen atoms joined into long strands.
  • Explains that tin-plated steel could have important applications as high-efficiency insulators and radiation detectors.
  • Explains that plastic coatings have replaced tin in many food containers, and aluminum in making cans has dropped sharply. steel is plated by dipping sheets of it in molten steel or by passing continuous strips on high-speed rubber rollers
  • Explains that tin is a constituent of alloys having low melting points, such as bronze, babbitt metal, type metal and solder metal.
  • Explains that tin can form a bond with carbon, as in the more than 500 organotine compounds, used in making wood, paper, paint, textile products, agricultural sprays, and hospital disinfectants.
  • Explains that tin is refined by electrolysis. china led the world in production in the 1990s, followed by brazil, indonesia, malaysia, and bolivia.
  • Explains that the international tin council (itc), a cartel, supported artificially high prices for tin while world use dropped.
  • Explains that the itc suspended export controls in 1985, but the association of tin producing countries reinstituted quotas in 1987.
  • Explains that tin concentrates were produced from placer deposits in alaska, and a major secondary source is scrap, which is recovered at detinning plants. bronze alloyed with copper ushered in the bronze age of civilization.
  • Describes germanium, a brittle silver element predicted in 1871 by mendeleev but not discovered until 1886 by clemens winkler.
  • Explains that superconductor in electronics, window and lens component in equipment to measure infrared radiation, and transistors and in phosphors for fluorescent lamps. it can kill certain harmful bacteria without causing toxicity to humans.
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