Published March 11, 2017
Twenty-first century is called the time of products from polymers. Polymers are inorganic or organic, amorphous and crystalline substances consisting of "monomeric units" connected in long macromolecules by chemical bonds. The polymers consist of a large number of repeating units of the same structure, for example, polyvinyl chloride, natural rubber, and others...
Published March 11, 2017
Acetylene is unsaturated hydrocarbon, colorless, flammable gas, slightly lighter than air and has a pungent odor. It has a triple bond between the carbon atoms belongs to the class of alkynes. Ethylene - is a colorless gas with a faint ethereal odor. It is the simplest alkene. It has a double bond, and therefore refers to unsaturated hydrocarbons...
Published March 11, 2017
The Earth's crust is found sulfur in the free state and bound form. Sulfur in the native state, as well as in the form of sulfur compounds is known from ancient times. With the smell of burning sulfur, suffocating effect of sulfur dioxide and hydrogen sulfide humanity met, probably in prehistoric times...
Published March 11, 2017
Potash (K2CO3) – potassium carbonate, one of the salts known to people in ancient times. Usually potassium contaminated with various impurities, so does not have such a pure white color, like crushed potassium carbonate. Until the 20th century in Europe, potash was one of the most important industrial chemicals...
Published March 11, 2017
Phosphorus is a chemical element with atomic number 15 in the third period of the periodic system of elements. This is one of the most common elements of the earth's crust: its content is 0,08-0,09% of its mass. The concentration of phosphorus in sea water is 0,07 mg/l. In a free state phosphorus does not occur because of high chemical activity...
Published March 11, 2017
Today, cement is indispensable in the construction. It is the main component of concrete solution. Without cement not get solid building blocks, not to build any bridge or building, no stadium, no airport. A particularly important property of the cement is hardening in water. Even in ancient times to make lime ability to harden in water was added thereto natural volcanic product puzzolana or artificial a brick dust...
