Up to the XIII century, people knew only nine chemical elements: seven metals - gold, silver, copper, tin, iron, lead and mercury, as well as two non-metals - sulfur and carbon. Then the period of alchemy lasted for five hundred years, and over the years as byproducts of intense alchemical quest five chemical elements were discovered: arsenic, antimony, zinc, bismuth and phosphorus.

In the first half of the XVIII century they were discovered platinum, cobalt and nickel. Thus, two hundred and fifty years ago, the mankind knew only 17 chemical elements.

March 1, 1869 Dmitri Ivanovich Mendeleev (1834-1907) published a table of "Trying system elements based on their atomic weight and chemical similarity", which included a little more than six dozen items. Two years later, in 1871, significantly developing the idea of the periods and a group of elements and the place of the element in the system, the scientist called it the periodic system. As a result that periodic system already largely acquired modern structural shapes.

At present there are 112 (114 according to other sources) of the chemical elements, firmly "lock in" their place in the periodic table of Mendeleev. without which It is impossible to imagine any one chemical class at school or a chemical laboratory at the Institute and the University without this table. The elements starting with the numbers starting from one hundred and ten, have not yet received permanent names.

I probably will not be wrong if I say that each of us, for the first time entering the classrooms of chemistry, was shocked by numerous banks, flasks, test tubes on the shelves, tables and cabinets, solutions, powders and crystals of all colors and shades, unclear labels and formulas not similar to the math. Then we began to navigate in this diversity and were surprised to learn that we are and all that surrounds us, consists of only nine dozen chemical elements. A lot of them in pure as well as in chemical compounds were hidden in these glass vessels of chemical classroom.

Interestingly, how many chemical elements there is in a normal city apartment or a country house? At first glance, it may seem strange, but if you look closely, you can find out in what we have at home there are present almost all the "representatives" of the periodic system!

Let's begin with the first and easy one - the hydrogen. The basic chemical composition, in which there is the hydrogen, is the water. It is hard to imagine a home without water: with its help we finally wake up, quench a thirst, support all clean. Finally, none of the food product supply can exist without hydrogen naturally associated. Thus, hydrogen has the honorary first place not only because it is the easiest!

The second element included in the water, whose role in our existence no less than hydrogen, and maybe even more, is oxygen. Try to hold your breath and a few tens of seconds to do without one fifth of the air. Tried? That's it! The oxygen has no odor or taste, but its value is not diminished by this. By the way, about the smell - after the storm when we breathe in the fresh air, then be happy to feel peculiar smell of a modification of oxygen - ozone.

Together with the oxygen another element – nitrogen - penetrates in our lungs nitrogen. However, in contrast to the oxygen, it almost does not stay therein. However, a huge amount of nitrogen in our body gets from food proteins in the composition. And what help we can sometimes provide one of the components of our first aid kit - ammonia consisting of nitrogen, hydrogen and oxygen!

Two other elements - fluorine and chlorine – exist in home only in the form of harmless compounds. Both of them in conjunction with the carbon in the form of refrigerant cool the food and drinks in our fridge, as well as "help" cosmetics and paint materials under pressure "to leave" spray cans. Fluorine plays a significant role in our daily fight against tooth decay. Well, we consume a huge amount of chlorine with table salt!

If we remember about fluorine and chlorine, let’s speak about the other halogens - bromine and iodine. With iodine (though in the form of an alcoholic solution) we treated our scratched knees in childhood, while bromine in very small amounts exists in the already mentioned common salt. In addition, silver bromide in the composition used in the photo element, and solutions of sodium and potassium bromide - as sedatives.

Among the gases still there are in our table so-called inert helium, neon, argon, krypton, xenon and radon. All of them are in the air we breathe. A powerful stream of light flash when photographing provides xenon, but if you look out the window, you can see the colored letters advertising signs on the shops and cafes – this is a "work" of neon (incidentally, this green color to discharge lamps is provided by halogens thallium).

There are in these flash lamps the rhenium and the hafnium. This hafnium foil directs a stream of bright light.

Let us speak now about metals in detail.

Alkali metals - lithium, sodium, potassium, rubidium, and cesium - instantly react with oxygen and may therefore be present only in our house in the form of compounds. If your family has a smokers or motorists, then there are no problems with lithium: lithium salts in sufficient quantity contained in tobacco and in the electrolyte alkaline battery. Lithium is also a member of glass television picture tubes. Sodium (with chlorine) in the form of salt we use in our food, and potassium, if you personally deal with not only taking pictures but also print photos, in form of potash - potassium carbonate, - will be at your home. In addition, potassium is present in the crystal glass, well and sodium - the window. If your home is protected, than it is very likely there are here rubidium and cesium, which are included in the motion sensors of alarm system.

Aluminum, the "winged" metal, copper, may be unseen to our eyes, entangle us from all sides: the walls and ceilings, and electric vacuum cleaner, refrigerator and washing machine - all these metals are present in the form of wires. Aluminum also allows us to see ourselves in the mirror: a thin film of metal deposited on the back side of the mirror. Previously used for this purpose silver (now also produced "silver" mirror, but they are more expensive than "aluminum" one). Considering the black-and-white photographs, many of us do not realize that their composition is metallic silver. Silver is also a member of jewelry and coins.

Among jewelry a special place is occupied by a ring which is usually made of gold-based alloys. In addition, gold and silver cover the most critical contacts chips that make up the radios, televisions, computers ...

Platinum is much less common in jewelry. But if your family members had special merits before the Soviet Union, and they were awarded by orders, than there is a platinum in your home because these orders contain this metal (for example, the Order of Lenin). Also in jewelry it is used rhodium in small quantities (typically platinum alloys).

Iron is especially honored metal. Unfortunately, "thanks to" his "love" to atmospheric oxygen, iron around us is only present in the alloy with other elements. Steel and cast iron cookware, furniture, metalwork and carpentry tools ... Although today there are attempts to replace the iron by different plastics, with full confidence we can say that this metal is more than one decade will be the basis of our "iron" age.

If you look to the kitchen, the first thing that catches your eye is a brilliant cookware. Much of it is made of stainless steel, which usually includes not only chromium and nickel, but also a "space" metal such as titanium. Titanium, in addition, also contained in the titanium paint which is used to cover the windows’ frames. Chromium and nickel also make attractive the metal parts of bicycle which stands in the hallway or on the balcony.

Look at the tool box! At first glance everything here is made from ordinary steel, but almost every drill contains tungsten and molybdenum, there are chromium and vanadium in spanners, and in the hacksaw - chromium and tungsten, and vanadium.

If you still have a transistor radio, you can find indium and selenium in transistors. The basis of the "brain" of modern "smart" assistants - household appliances – is consists of semiconductor materials: silicon, germanium and a little bit less - gallium. But despite the broad offensive of integrated circuits, even experts now recognize that high-quality sound equipment uses no chips, but almost forgotten vacuum radio tubes, which "grid" is made of molybdenum wire. In the composition of components of such lamps there are scandium, niobium, tantalum, strontium, tungsten. Without the latter, is very hard to imagine an incandescent lamp.

Calcium in its pure form, unlike mercury, which is "hidden" in a medical thermometer, in our house you will not find because of its high activity. But look at the white ceiling (if you have not stuck by wallpaper): whitewash - a calcium carbonate.

Many years ago, magnesium metal in powder form has always been in the arsenal of photographers: it gave a brilliant flash when “a bird flew” out the camera lens. The magnesium compounds, in particular sulfate or oxide, today can be found in the home medicine cabinet due to their effective ability to "liberate" the intestinal tract of unnecessary substances.

It is impossible to find a metal barium at home, however, barium sulfate is present in the photographic paper, cardboard, linoleum, and possibly in the rubber. By the way, in the rubber bicycle tire we will find sulfur, but more often we are dealing with it, picking up matches. But phosphorus is part of the mixture coated on a matchbox. If you are not using matches, a lighter, cerium “hides” in its silicon.

In order to get rid of some "domestic" animals different poisons are used: against cockroaches - the borax, which includes boron, but against rats - arsenic.

Carbon is the foundation of life on our planet. Thanks to him, you know all the news: carbon is part of the ink. Finally, try to imagine life without a pencil, the core of the pencil is made of graphite - allotropic modification of carbon!

Tin can be found in tinplate tin or soldering alloy of radio amateur, and lead - in fishing sinkers or car battery plates (the antimony is used also in these plates ). Also, the bismuth is used as a component of the solder, its oxides - as antiseptic drugs.

Listening to your favorite cassette or disc, you should be grateful to zinc and cadmium, which are part of the battery of the player (although today's leading companies are trying to make the batteries without cadmium compounds). Cadmium is also part of oil-based paints, which "play" in the paintings by wonderful bright yellow color.

Beryllium is found in many bronzes, which are used in clockworks, manganese can be found in the usual - potassium permanganate, and vanadium - in car parts and permanent magnets, which can be "found" in the radio and furniture place.

Cobalt oxide provides a magnificent blue patterns on chinaware and metallic cobalt is part of the famous alloy "pobedit", which allows you to make any holes in the concrete.

Raincoats and tourist tents owe their moisture resistance to zirconium salts, which are part of emulsions for impregnating fabrics.

Palladium can be found in the form of an alloy with the platinum catalysts in automobile exhaust gas afterburning. If, God forbid, you lose one or more teeth, you can use fairly efficient denture with a palladium alloy.

The exotic metals can be found in a conventional ballpoint pen ball: osmium, iridium, ruthenium!

Yttrium oxide activated with europium is a red phosphor for color TV screens and computer monitors. The composition of the glass of kinescopes includes strontium, which with the other components gives us a unique paint (no wonder strontium chloride is also used in cosmetics).

By the way, until recently, the house could be found depleted uranium (uranium amplifier in the photo), thorium (thorium nitrate in the form of magnesium flares in the pictures), and even radium (salts causes the light dials old clock).

Well, go on?! As you can see, our house is full of "representatives" one of the greatest of mankind tables - Periodic Table of Elements. Even each of us "consists" of twenty four chemical elements: hydrogen, oxygen, carbon, nitrogen, potassium, calcium, sulfur, iron, zinc, chlorine, phosphorous, iodine, fluorine, copper, cobalt, chromium, magnesium, molybdenum, arsenic, selenium, vanadium, nickel, silicon and tin. So let's not be afraid of chemistry or treat it with prejudice, but thank her for a variety of necessary and just nice things that surround us!