CHEMISTRY

Reviewed by GL: And your sources of information?

Germanium is one of the semimetals or metalloids that are those who have properties similar to those of the metals and not metals. Its atomic number is 32, its symbol Ge, its group is 14, its period 4, block P, atomic Mass 72,64, density 5.35, specific heat 0.32, point of merger 960, formula of oxide GeO2, formula of chloride GeCL4, density of oxide 4,70, boiling-point of chloride 86, gray color and condition of the matter: solid. As an example it is used for photographic glases. The properties of the germanium were predicted in 1871 by Mendeleyev depending on its position in the periodic table, element to which it called eka-silicon. The German Clemens Winkler demonstrated in 1886 the existence of this element, discovery that served to confirm the validity of the periodic table. The germanium is more commonly in the nature as a pollutant of diverse minerals and is obtained of the remaining residues of cadmium of the accused of the minerals of zinc. The toxicological investigations have demonstrated that the germanium is not located in any fabric provided that it is excreted rapidly principally by the urine. The excessive doses of germanium injure the capillary beds of the lungs. It produces a very marked diarrhea that provokes a dehydration, hemoconcentración, fall of the arterial pressure and hipotermia. The germanium has five stable isotopes being the most abundant the Ge-74 (35,94 %). 18 have been characterized radioisótopos of germanium, being the Ge-68 that of major average life with 270,8 days. 9 conditions are known in addition metaestables.

sources of information: www.kalipedia .com www.wikipedia.com

Why water is important? 1We are made 70% of water (in our blood, Saliva…). 2The water is occupies a big space in our planet (ocean, lakes, river, cloud …). 3Also is with us alll the time (air). 4Is in the things we eat (food). 5If we not have water we will be in serious problems (droughts, we can die...). 6The water regulates the climate of the Earth (temperautre). 7With out the 70% that the water gives us we can’t be able to satisfy us (we will have heat). 8We would get weak. 9With out mineral we can't hydrate ourselves. 10The water is also important for other living-things (animals or plants).