IPA Lesson
WATER
Water is an essential compound for all known forms of life on Earth to date, [1] [2] [3] but not on another planet. [4] Water covers nearly 71% of the Earth's surface. There are 1.4 billion cubic kilometers (330 million miles ³) is available on Earth. [5] Air are mostly found in the sea (salt water) and in the layers of ice (in polar and mountain tops), but may also be present as clouds, rain, rivers, freshwater front, lake, water vapor, and sea ice. The water in these objects move follows a cycle of water: through evaporation, rain, and the water flow over the surface of the ground (runoff, including springs, rivers, estuaries) to the sea. Clean water is essential for human life.
In many places in the world there is a shortage of water supply. In addition to the Earth, a large amount of water is also estimated that there are at the north and south poles of Mars, as well as in the months of Europa and Enceladus. Water can be either solid (ice), liquid (water) and gas (water vapor). Water is the only substance which is naturally present on the surface of the Earth in its form the third. [6] Management of water resources is not good to cause water shortages, monopolisation and privatization and even spark conflicts. [7] Indonesia has laws governing water resources since 2004, namely Law No. 7 of 2004 on Water Resources
Water
is a chemical substance with chemical formula H2O: one molecule of
water is composed of two hydrogen atoms covalently bonded to one oxygen
atom. Water
is colorless, tasteless and odorless at standard conditions, ie at a
pressure of 100 kPa (1 bar) and temperature of 273.15 K (0 ° C). This
chemical is an important solvent, which has the ability to dissolve
many other substances, such as salts, sugars, acids, some types of gas
and many kinds of organic molecules.The
state of liquid water is a situation which is not common in normal
conditions, especially with respect to the relationship between the
other hydrides are similar in oxygen column on the periodic table, which
suggests that water should be a gas, like hydrogen sulfide. Having
regard to the periodic table, it appears that the elements surrounding
oxygen is nitrogen, fluorine, and phosphorus, sulfur and chlorine. All of these elements when bonded to hydrogen will produce gas at normal temperature and pressure. The
reason why hydrogen bond with oxygen to form berkeadaan liquid phase,
is because oxygen is more electronegative than the other elements
(except fluorine).