1. Group 1 Silicon ~ Phosphorus By: Tyretel Iancu~Leah Caluya~Nya Tokyo

2. Silicon: Atomic number: 14 Atomic number: 14 Atomic Symbol: Si Atomic Symbol: Si Atomic Weight: 28.086 Atomic Weight: 28.086 Atomic Radius: 117 pm Atomic Radius: 117 pm Electron Configurations: [Ne]3 s 2 3 r 2 Electron Configurations: [Ne]3 s 2 3 r 2 Melting Point: 1414 ?C Melting Point: 1414 ?C Boiling Point: 3265 ?C Boiling Point: 3265 ?C Oxidation State: 2, 4, -4 Oxidation State: 2, 4, -4 Silicon symbol

3. History: 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.

4. Sources: Silicon can be found in: – The Sun – The Stars – Certain Meteorites called aerolites – Tektites (glass with unknown origins).

5. 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.

6. Properties: Crystalline-metallic luster grayish color. Inert element It is attacked by halogens and dilutes alkali. Most acids do not affect it.

7. 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.

8. Images:

9. Silicon

10. Silicon electron arrangement

13. Phosphorous Atomic Number: 15 Atomic Number: 15 Atomic Symbol: P Atomic Symbol: P Atomic Weight: 30.97376 Atomic Weight: 30.97376 Electron Configuration: [Ne]3s23p3 Electron Configuration: [Ne]3s23p3 Atomic Radius: 93 pm Atomic Radius: 93 pm Melting Point: 44.15 (white phosphorus) Melting Point: 44.15 (white phosphorus) Boiling Point: 280.5 (white phosphorous) Boiling Point: 280.5 (white phosphorous) Oxidation State: 5, 3, -3 Oxidation State: 5, 3, -3 Phosphorus symbol

14. 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.

15. 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.

16. Uses 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.

17. Uses (continued) 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.

18. Properties Phosphorus exists in four or more allotropic forms: white (or yellow), red, and black (or violet). Ordinary phosphorus is a waxy white solid. 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. 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. It is insoluble in water, but soluble in carbon disulfide. It takes fire spontaneously in air, burning to the pent oxide.

19. Interesting Facts: Phosphorus is also an essential ingredient of cell protoplasm, nervous tissue, and bones. Phosphorus is also an essential ingredient of cell protoplasm, nervous tissue, and bones. Different colors aka types of phosphorus. Different colors aka types of phosphorus. When it is pure it is colorless. When it is pure it is colorless.

20. Phosphorus Electron arrangement

25. Cited Sources: “Silicon.” www.periodic.lanl.govwww.periodic.lanl.gov “Phosphorus.” www.periodic.lanl.govwww.periodic.lanl.gov

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