C5- Chemicals of the natural environment

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  • Created by: Priya
  • Created on: 31-01-12 14:03

Ionic Bonding- As a sodium chloride crystal forms, millions of Na+ ions and millions of Cl- ions pack closely together. The ions are held together very strongly by the attraction between the opposite charges. This is called ionic bonding, and the structure is called a giant ionic structure. Unlike compounds such as water which is made of of individual molecules of H20, there is not an individual NaCl molecule.

Because of the strong attractive forces, it takes a lot of energy to break down the regular arrangement of ions.

Covalent Bonding- Instead of forming small molecules, the compound forms a three-dimensional covalent structure. The bonds are very strong, so the structure is strong and rigid. The structure does not conduct electricity because there are no free electrons or ions. It is also insoluble in water, so cannot be made to conduct electricity. There is a high melting point and boiling point so the structure is difficult to break down.

Extracting Metals- The more reactive the metal, the harder to reduce its ore.

Metal ores are mined in different parts of the world. If ore is not very pure, it may not be worth using - the cost of concentrating the ore may be too great. The more valuable the metal, the lower the quality of the core which can be used.

It takes energy to extract metals, as well as a good supply of ore. This is especially true if…

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rezaul

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this is great exactly what i need :)