CHEMISTRY

Reviewed by GL: Well done!


 * 3 Term **


 * Homework 3:

1. Complement the Class by finding out the definitions, properties and examples of the separation techniques by chemical methods. - Evaporation:** Is a process in wich liquid evaporates and turn to a vapor form. Example: The water boils in the water cycle.
 * - Decantation:** Is the process in wich liquid separates from a heavy solid. Example: Red wine.
 * - Filtration:** Is the process solid separates from fluids. Example: Coffee filtrer.
 * - Crystallization:** Is the process solid separates from gas. Example: Crystal.
 * - Sublimination:** Is the process that is a conversion of gas without liquid involed. Example: Small pellets.

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 * Homework 2 **:

1) Describe the importance of alloys, plastics and polymers in Society - We use it many times everyday. Examples: Containers for drinking, for paint, for food or medicine and in general in industries or print. They use it for print bags or do bags of markets. For graphicals or stamps.

2) Find and describe at least two different types of newest materials used in each of these: Medicine, Industry, and Sports. - In the Sports, the soccer balls, containers of water, plastic baseball ball, etc. - In Medicine, the containers of the capsules, of alcohol, etc. - In Industry, pens, toys, dishes, bags,cd holders, etc __**:**MANGANESE__

-The chemical symbol of Manganese is Mn. -The atomic number is 25 and the atomic mass is 54.9380. -Manganese was discovered in 1774 by a Swedish chemist called Carl Wilhelm Scheele. -Is on the group of transition metals in period 4. -Manganese became from the latin word **magnes. __Electronic configuration:__** -1s2 2s2 2p6 3s2 3p6 4s2 3d5 [AR] 4s2 3d5 - Ionization energy:** 7.434 eV - **Electronegativity:** 1.55 - **Electron Affinity:** 0 kJ mol-1 **- Atomic radius:** 127 pm **2. Uses of the element:** Manganese is distribuited through the animal kingdom. It is an important element for the vitamin B1. **3. Economic Impact:** Manganese is very important for the economy. Manganese is found as a trace mineral that is described as a free element and have metal properties.
 * 1. Properties and characteristics : **
 * __Periodic Properties :__