Group 1
Silicon ~ Phosphorus
By: Tyretel Iancu~Leah Caluya~Nya
Tokyo
Silicon:
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Atomic number: 14
Atomic Symbol: Si
Silicon symbol
Atomic Weight: 28.086
Atomic Radius: 117 pm
Electron Configurations: [Ne]3s23r2
Melting Point: 1414 ?C
Boiling Point: 3265 ?C
Oxidation State: 2, 4, -4
History:
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1800 ~ Davy thought silica was a compound, not an
element.
1811 ~ Lussac and Thenard did an experiment by
heating potassium and silicon tetrafluoride, creating
amorphous silicon, proving that Davy was wrong.
1824 ~ Berzelius did the same experiment, this time
making the silicon a pure substance by removing the
fluosilicates by repeated washing.
Sources:
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Silicon can be found in:
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The Sun
The Stars
Certain Meteorites called aerolites
Tektites (glass with unknown origins).
Uses:
 Concrete and brick
 Enamel, pottery, etc.
 Main ingredient in glass
 Most inexpensive materials with mechanical,
optical, thermal, and electrical properties.
 Silicon can be combined with other elements to
be used for transistors, solar cells, rectifiers, and
other solid-state devices.
Properties:
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Crystalline-metallic luster grayish color.
Inert element
It is attacked by halogens and dilutes alkali.
Most acids do not affect it.
Interesting facts:
 Elemental silicon transmits more than
95% of infrared waves.
 Costs:
 99%
silicon costs about 50 cents /g
 99.9% pure silicon costs 50 dollars /lbs.
 Hyper pure silicon can cost 100 dollars /oz.
 Important to plant an animal life.
 Silicon makes up 25.7% of the earch’s crust,
by weight, and is the second most abundant
element, being exceeded only by oxygen.
Images:
Silicon
Silicon
electron arrangement
Phosphorous
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Atomic Number: 15
Phosphorus symbol
Atomic Symbol: P
Atomic Weight: 30.97376
Electron Configuration: [Ne]3s23p3
Atomic Radius: 93 pm
Melting Point: 44.15 (white phosphorus)
Boiling Point: 280.5 (white phosphorous)
Oxidation State: 5, 3, -3
History
Gr. phosphoros: light bearing; ancient
name for the planet Venus when
appearing before sunrise
In 1669, Brand discovered phosphorus by
making it from a body fluid.
Sources
 Phosphorus cannot be found in nature.
 It can be found in minerals.
 Phosphate rock contains mineral apatite,
which is an impure tri-calcium phosphate,
is an important source of the element.
 In Russia, Morocco, Florida, Tennessee,
Utah, Idaho and a few other places, large
deposits of phosphorus can be found.
Uses
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Phosphoric acids, which have 70% to 75%
phosphorous, have been important to
farmers. It makes very good fertilizer.
Phosphates are used for making special glass
used in sodium lamps.
Bone-ash --calcium phosphate-- is used to
make fine china.
And the mono-calcium phosphate, used in
baking powder.
Uses (continued)
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It is also important for making different
types of steels and phosphor bronze.
Trisodium phosphate is used as a
cleaning agent, a water softener, and
prevents boiler scale and corrosion of
pipes and boiler tubes.
Properties
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Phosphorus exists in four or more allotropic forms:
white (or yellow), red, and black (or violet). Ordinary
phosphorus is a waxy white solid.
White phosphorus has two modifications: alpha and
beta with a transition temperature at - 3.8oC.
It is insoluble in water, but soluble in carbon
disulfide. It takes fire spontaneously in air, burning to
the pent oxide.
Interesting Facts:
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Phosphorus is also an essential
ingredient of cell protoplasm, nervous
tissue, and bones.
Different colors aka types of
phosphorus.
When it is pure it is colorless.
Phosphorus
Electron arrangement
Cited Sources:
• “Silicon.” www.periodic.lanl.gov
• “Phosphorus.” www.periodic.lanl.gov
Bye…..u can go now……GO AWAY!!!!>_<