Inorganic substances - such chemical compounds that, unlike organic ones, do not contain carbon (except for cyanides, carbides, carbon oxides, carbonates and some other compounds traditionally belonging to this group).
The classification of inorganic substances is as follows. There are simple substances: non-metals (H2, N2, O2), metals (Na, Zn, Fe), amphoteric simple substances (Mn, Zn, Al), noble gases (Xe, He, Rn) and complex substances: oxides (H2O, CO2, P2O5); hydroxides (Ca (OH) 2, H2SO4); salts (CuSO4, NaCl, KNO3, Ca3 (PO4) 2) and binary compounds.
Molecules of simple (single-element) substances consist only of atoms of a certain (single) type (element). They do not decompose in chemical reactions and are not capable of forming other substances. Simple substances, in turn, are divided into metals and non-metals. A clear boundary between them does not exist due to the ability of simple substances to exhibit dual properties. Some elements simultaneously exhibit the properties of both metals and non-metals. They are called amphoteric.
Noble gases are inorganic substances of a separate class; they stand out among others by a special originality. These are elements of the VIIIA group.
The ability of some elements to form several simple ones that differ in structure and properties is called allotropy. Examples are elements C forming diamond carbine and graphite; O - ozone and oxygen; P - white, red, black and others. This phenomenon is possible due to the different number of atoms in the molecule and due to the ability of atoms to form different crystalline forms.
In addition to simple, the main classes of inorganic substances include complex compounds. Complex (two- or multi-element) substances are understood to mean compounds of chemical elements. Their molecules are composed of atoms of different types (different elements). When decomposed in chemical reactions, they form several other substances. Divided into bases, oxides, acids and salts.
In the bases, metal atoms are connected to hydroxyl groups (or one group). These compounds are divided into soluble (alkali) and insoluble in water.
Oxides consist of two elements, one of which is necessarily oxygen. They are non-salt forming and salt forming.
Hydroxides are substances that are formed by the interaction (direct or indirect) with water. These include: bases (Al (OH) 3, Ca (OH) 2), acids (HCl, H2SO4, HNO3, H3PO4), amphoteric hydroxides (Al (OH) 3, Zn (OH) 2). When different types of hydroxides interact with each other, oxygen-containing salts are formed.
Salts are divided into medium (they consist of cations and anions - Ca3 (PO4) 2, Na2SO4); acidic (they contain hydrogen atoms in the acid residue, which can be replaced by -NaHSO3, CaHPO4 cations), basic ones (they have a hydroxy or oxo group - Cu2CO3 (OH) 2); double (contain two different chemically cations) and / or complex (contain two different acid residues) salts (CaMg (CO3) 2, K3 [Fe (CN) 6]).
Binary compounds (a fairly large class of substances) are divided into oxygen-free acids (H2S, HCl); oxygen-free salts (CaF2, NaCl) and other compounds (CaC2, AlH3, CS2).
Inorganic substances do not have a carbon skeleton, which is the basis of organic compounds.
In the human body there are both organic substances (34%) and inorganic compounds. The latter include, first of all, water (60%) and calcium salts, of which the human skeleton mainly consists.
Inorganic substances in the human body are represented by 22 chemical elements. Most of them are metals. Depending on the concentration of elements in the body, they are called micro- (the content in the body of which is not more than 0.005% of body weight) and macrocells. Essential minerals for the body are iodine, iron, copper, zinc, manganese, molybdenum, cobalt, chromium, selenium, fluorine. Their intake with food into the body is necessary for its normal functioning. Macronutrients such as calcium, phosphorus and chlorine are the basis of many tissues.