The whole world around us consists of microscopic particles. Combining, they form simple and complex substances with different properties and character. How to distinguish one from the other? What characterizes complex chemicals?
Essence of substance
Science knows 118 chemical elements. They all represent atoms, the smallest particles that can react. The chemical properties of the elements depend on their structure. Independently, they cannot exist in nature and will certainly unite with other atoms. So they form simple and complex substances.
They are called simple if they consist of only one kind of atoms. For example, oxygen (O) is an element. Two of its atoms, connected together, form a molecule of a simple substance oxygen with the formula O2. When three oxygen atoms are combined into a molecule, ozone is obtained - O3.
Complex substance is the combination of different elements. For example, water has the formula H2O. Each of its molecules consists of two hydrogen atoms (H) and one oxygen atom. In nature, there are much more such substances than simple ones. These include sugar, s alt,sand, etc.
Complex Substances
Complex compounds are formed as a result of chemical reactions, with the release or absorption of energy. In the course of such reactions, hundreds of different processes are carried out in the world, many of them are directly important for the life of living organisms.
Depending on the composition, complex substances are divided into organic and inorganic. All of them have a molecular or non-molecular structure. If the structural unit of matter is atoms and ions, these are non-molecular compounds. Under normal conditions, they are solid, melt and boil at high temperatures. These can be s alts or various minerals.
In another type of structure, two or more atoms combine to form a molecule. Inside it, the bonds are very strong, but it interacts weakly with other molecules. They come in three states of aggregation, usually volatile, often odorous.
Organic Compounds
There are about three million organic compounds in nature. They do contain carbon. In addition to it, compounds often contain some metals, hydrogen, phosphorus, sulfur, nitrogen and oxygen. Although, in principle, carbon is able to combine with almost any element.
These substances are part of living organisms. These are valuable proteins, fats, carbohydrates, nucleic acids and vitamins. They are found in food, dyes, fuels, form alcohols, polymers and other compounds.
Organic substances, as a rule, have a molecular structure. In this regard, they often exist in liquid and gaseous states. They have lower melting and boiling points than inorganic compounds and form covalent bonds.
Carbon combines with other elements, forming closed or open chains. Its main feature is the ability to homology and isomerism. Homologues are formed when other CH2 pairs are added to the CH2 (methane) pair, forming new compounds. Methane can be converted to ethane, propane, butane, pentane, etc.
Isomers are compounds with the same mass and composition, but different in the way the atoms are connected. In this regard, their properties are also different.
Inorganic compounds
Inorganic compounds do not contain carbon. The only exceptions are carbides, carbonates, cyanides and oxides of carbon, for example, chalk, soda, carbon dioxide and carbon monoxide and some other compounds.
There are fewer complex inorganic compounds in nature than organic ones. They are characterized by a non-molecular structure and the formation of ionic bonds. They form rocks and minerals and are present in water, soil and living organisms.
Based on the properties of substances, they can be divided into:
- oxides - the bond of an element with oxygen with an oxidation state of minus two (hematite, alumina, magnetite);
- s alts - the bond of metal ions with an acidic residue (rock s alt, lapis, magnesium s alt);
- acids - the bond of hydrogen and an acidic residue (sulfuric, silicic, chromic acid);
- bases - the bond of metal ions and hydroxide ions (caustic soda, slaked lime).
