1. Cobalt Wong Siu Man (43) Tong Yuk Choi(39) Chan Chun Chung(25) Law Chung Kwong(33)

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3. Background Information a chemical element with symbol Co and atomic number 27 Melting point is 1495°C, boiling point 2927°C It is found naturally only in chemically combined form. Hard, silver-gray metal Pure cobalt is not found in nature, but compounds of cobalt are common

4. Testing water Cobalt chloride paper is paper soaked in cobalt(II) chloride (CoCl 2 ) solution. It is used to test for the presence of water because it turns from blue to pink upon exposure to water. CoCl 2 (blue) + 6 H 2 O → [Co(H 2 O) 6 ]Cl 2 (pink)

5. Alloys Cobalt-based super alloys consume most of the produced cobalt makes them very hard and wear resistant. The temperature stability of these alloys makes them suitable for use in aircraft engines

6. Cobalt Glass Cobalt glass is a deep blue colored glass prepared by adding cobalt compounds to the molten glass. It is appreciated for its attractive color

7. Gamma ray source Cobalt-60 is useful as a gamma ray source sterilization of medical supplies, medical waste and density measurements Cobalt-60 has a radioactive half-life about 5 years. Cobalt-57 most often used in medical tests

8. Other usage of Cobalt Lithium cobalt oxide (LiCoO 2 ) is widely used in lithium ion battery cathodes Other uses of cobalt are in electroplating, attractive appearance, hardness and resistance to oxidation

9. The End, Thank You