Man has always sought to find materials that leave no chance for their competitors. Since ancient times, scientists have been looking for the hardest materials in the world, the lightest and heaviest. The thirst for discovery led to the discovery of an ideal gas and an ideal black body. We present you the most amazing substances in the world.
1. The blackest substance
The blackest substance in the world is called Vantablack and consists of a collection of carbon nanotubes (see carbon and its allotropic modifications). Simply put, the material consists of countless "hairs", hitting which, the light bounces from one tube to another. In this way, about 99.965% of the light flux is absorbed and only a negligible part is reflected back to the outside.
The discovery of Vantablack opens up broad prospects for the use of this material in astronomy, electronics and optics.
2. The most combustible substance
Chlorine trifluoride is the most flammable substance ever known to mankind. It is the strongest oxidizing agent and reacts with almost all chemical elements. Chlorine trifluoride can burn through concrete and easily ignites glass! The use of chlorine trifluoride is almost impossible due to its phenomenal flammability and the inability to ensure the safety of use.
3. The most poisonous substance
The most powerful poison is botulinum toxin. We know it under the name Botox, that is how it is called in cosmetology, where it has found its main application. Botulinum toxin is a chemical produced by the bacteria Clostridium botulinum. In addition to the fact that botulinum toxin is the most toxic substance, it also has the largest molecular weight among proteins. The phenomenal toxicity of the substance is evidenced by the fact that only 0.00002 mg min / l of botulinum toxin is enough to make the affected area deadly for humans for half a day.
4. The hottest substance
This is the so-called quark-gluon plasma. The substance was created using the collision of gold atoms at almost the speed of light. Quark-gluon plasma has a temperature of 4 trillion degrees Celsius. For comparison, this figure is 250,000 times higher than the temperature of the Sun! Unfortunately, the lifetime of matter is limited to one trillionth of a trillionth of a second.
5. The most corrosive acid
Antimony fluoride H becomes the champion in this nomination. Antimony fluoride is 2×10 16 (two hundred quintillion) times more caustic than sulfuric acid. This is a very active substance that can explode when a small amount of water is added. The fumes of this acid are deadly poisonous.
6. The most explosive substance
The most explosive substance is heptanitrocuban. It is very expensive and is used only for scientific research. But a slightly less explosive HMX is successfully used in military affairs and in geology when drilling wells.
7. The most radioactive substance
Polonium-210 is an isotope of polonium that does not exist in nature, but is made by man. It is used to create miniature, but at the same time, very powerful energy sources. It has a very short half-life and is therefore capable of causing severe radiation sickness.
8. The heaviest substance
It is, of course, fullerite. Its hardness is almost 2 times higher than that of natural diamonds. You can read more about fullerite in our article The Hardest Materials in the World.
9. Strongest magnet
The world's strongest magnet is made up of iron and nitrogen. At present, details about this substance are not available to the general public, but it is already known that the new super-magnet is 18% more powerful than the strongest magnets currently in use - neodymium. Neodymium magnets are made from neodymium, iron and boron.
10. The most fluid substance
Superfluid Helium II has almost no viscosity at temperatures close to absolute zero. This property is due to its unique ability to seep and pour out of a vessel made of any solid material. Helium II has the potential to be used as an ideal thermal conductor in which heat does not dissipate.
SUBSTANCE
SUBSTANCE
kind of matter, which, in contrast to the physical. fields, has a rest mass. Ultimately, the wave is composed of elementary particles whose rest is not equal to zero (mostly from electrons, protons, neutrons). In the classic V. physics and physical. fields were absolutely opposed to each other as two types of matter, the first of which is discrete, and the second is continuous. Quantum, which introduced the idea of duals. corpuscular-wave nature of any micro-object, led to the leveling of this opposition. The revelation of the close interrelationship between water and the field led to a deepening of ideas about the structure of matter. On this basis, V. and matter were strictly delimited, throughout pl. centuries, identified both with philosophy and science, and philosophy significance remained with the category of matter, and V. retained the scientific one in physics and chemistry. Vacuum occurs under terrestrial conditions in four states: gases, liquids, solids, and plasma. It is stated that V. can also exist in a special, superdense (e.g. in neutron) condition.
Vavilov S. I., Development of the idea of matter, Sobr. op., t. 3, M., 1956, With.-41-62; Structure and forms of matter. [Sat. Art.], M., 1967.
I. S. Alekseev.
Philosophical encyclopedic dictionary. - M.: Soviet Encyclopedia. Ch. editors: L. F. Ilyichev, P. N. Fedoseev, S. M. Kovalev, V. G. Panov. 1983 .
SUBSTANCE
close in meaning to the concept matter, but not completely equivalent. Whereas the word "" is mainly associated with ideas about a rough, inert, dead reality, in which exclusively mechanical laws dominate, the substance is a "material", which, due to the receipt of a form, evokes form, life suitability, ennoblement. Cm. Gestalt weaving.
Philosophical Encyclopedic Dictionary. 2010 .
SUBSTANCE
one of the basic forms of matter. V. include macroscopic. bodies in all states of aggregation (gases, liquids, crystals, etc.) and the particles that form them, having their own mass ("rest mass"). A large number of types of particles are known in V.: "elementary" particles (electrons, protons, neutrons, mesons, positrons, etc.), atomic nuclei, atoms, molecules, ions, free radicals, colloidal particles, macromolecules, etc. (see Elementary particles of matter).
Lit.: Engels F., Dialectics of Nature, Moscow, 1955; his own, Anti-Dühring, M., 1957; V. I. Lenin, Materialism and empirio-criticism, Soch., 4th ed., vol. 14; Vavilov S. I., Development of the idea of matter, Sobr. soch., vol. 3, M., 1956; his, Lenin and modern, ibid; his own, Lenin and the philosophical problems of modern physics, ibid.; Goldansky V., Leikin E., Transformations of atomic nuclei, M., 1958; Kondratyev VN, Structure and chemical properties of molecules, M., 1953; "Advances in Physical Sciences", 1952, vol. 48, no. 2 (dedicated to the problem of mass and energy); Ovchinnikov N. F., Concepts of mass and energy ..., M., 1957; Kedrov B. M., Evolution of the concept of an element in chemistry, M., 1956; Novozhilov Yu. V., Elementary particles, Moscow, 1959.
Philosophical Encyclopedia. In 5 volumes - M .: Soviet Encyclopedia. Edited by F. V. Konstantinov. 1960-1970 .
Synonyms:
Studying various areas of science within the framework of a school or university course, it is easy to notice that they very often operate with the concept of substance.
But what is a substance in physics and chemistry, what is the difference between the definitions of these two sciences? Let's try to take a closer look.
What is matter in physics?
Classical physics teaches that, of which the Universe consists, is in one of two basic states - in the form of matter and in the form of a field. Substance in physics is called matter, consisting of elementary particles (for the most part they are neutrons, protons and electrons), forming atoms and molecules that have a rest mass other than zero.
The substance is represented by various physical bodies that have a number of parameters that can be objectively measured. At any time, you can measure the specific gravity and density of the substance under study, its elasticity and hardness, electrical conductivity and magnetic properties, transparency, heat capacity, etc.
Depending on the type of substance and external conditions, these parameters can vary within a fairly wide range. At the same time, each type of substance is characterized by a certain set of constant characteristics that reflect its quality indicators.
Aggregate states of substances
All substances existing in the Universe can be in one of the states of aggregation:
- in the form of a gas;
- in the form of a liquid;
- in a solid state;
in the form of plasma.
At the same time, many substances are characterized by transitional or boundary states. The most common of them are:
- amorphous, or glassy;
- liquid crystal;
- highly elastic. 
In addition, some substances under special external conditions can pass into the state of superfluidity and superconductivity.
What is a substance in chemistry?
Chemical science studies substances consisting of atoms, as well as the laws by which transformations of substances occur, called chemical reactions. Substances can exist in the form of atoms, molecules, ions, radicals, and mixtures thereof.
Chemistry divides substances into simple ones, i.e. those that consist of atoms of the same type, and complex, consisting of different types of atoms. Simple substances are called chemical elements: all substances in the world consist of them, like bricks.
During a chemical reaction, substances interact with each other, exchanging atoms and atomic groups, resulting in the formation of new substances. At the same time, chemistry does not consider processes in which changes occur in the atomic structure: the number and types of atoms involved in the reaction always remain unchanged.
All simple substances are summarized in the so-called periodic table of elements, which was created by the Russian scientist D.I. Mendeleev. In this table, simple substances are arranged in ascending order of their atomic masses and grouped according to their properties, which greatly simplifies their further study.
Organic and inorganic substances
In modern chemistry, it is customary to divide all substances into two main groups: inorganic and organic. Inorganic substances include:
— oxides- compounds of chemical elements with oxygen;
— acids- compounds consisting of hydrogen atoms and the so-called acid residue;
— salt- substances consisting of metal atoms and an acid residue;
— bases, or alkalis- compounds consisting of a metal and a hydroxyl group or several groups;
— amphoteric hydroxides Substances that have the properties of bases and acids.
There are also more complex compounds of inorganic elements. In total, there are up to half a million varieties of inorganic substances. 
Organic substances are compounds of carbon with hydrogen and other chemical elements. For the most part, they are complex molecules made up of a large number of atoms. There are many varieties of organic substances, depending on their composition and molecular structure. In total, at the moment, more than 20 million varieties of organic substances are known to science.
Relative molecular mass - mass (amu) 6.02 × 10 23 molecules of a complex substance. Numerically equal to the molar mass, but differs in dimension.
- Atoms in molecules are connected to each other in a certain sequence. Changing this sequence leads to the formation of a new substance with new properties.
- The connection of atoms occurs in accordance with their valency.
- The properties of substances depend not only on their composition, but also on the "chemical structure", that is, on the order of connection of atoms in molecules and the nature of their mutual influence. Atoms that are directly bonded to each other have the strongest influence on each other.
Thermal effect of the reaction- is the heat that is released or absorbed by the system during the course of a chemical reaction in it. Depending on whether the reaction occurs with the release of heat or is accompanied by the absorption of heat, exothermic and endothermic reactions are distinguished. The first, as a rule, includes all reactions of the connection, and the second - decomposition reactions.
The rate of a chemical reaction- change in the amount of one of the reacting substances per unit of time in a unit of reaction space.
Internal energy of the system- the total energy of the internal system, including the energy of interaction and movement of molecules, atoms, nuclei, electrons in atoms, intranuclear and other types of energy, except for the kinetic and potential energy of the system as a whole.
Standard enthalpy (heat) of formation of a complex substance- thermal effect of the reaction of formation of 1 mol of this substance from simple substances that are in a stable state of aggregation under standard conditions (= 298 K and a pressure of 101 kPa).
The main question that a person must know the answer to correctly understand the picture of the world is what is a substance in chemistry. This concept is formed at school age and guides the child in further development. When starting to study chemistry, it is important to find common ground with it at the everyday level, this allows you to clearly and easily explain certain processes, definitions, properties, etc.
Unfortunately, due to the imperfection of the education system, many people miss some fundamental basics. The concept of "substance in chemistry" is a kind of cornerstone, the timely assimilation of this definition gives a person the right start in the subsequent development in the field of natural science.
Concept formation
Before moving on to the concept of matter, it is necessary to define what the subject of chemistry is. Substances are what chemistry directly studies, their mutual transformations, structure and properties. In a general sense, matter is what physical bodies are made of.
So, in chemistry? Let us form a definition by passing from a general concept to a purely chemical one. A substance is a certain thing that necessarily has a mass that can be measured. This characteristic distinguishes matter from another type of matter - a field that has no mass (electric, magnetic, biofield, etc.). Matter, in turn, is what we are made of and everything that surrounds us.
A somewhat different characteristic of matter, which determines what exactly it consists of, is already the subject of chemistry. Substances are formed by atoms and molecules (some ions), which means that any substance consisting of these formula units is a substance.
Simple and complex substances
After mastering the basic definition, you can move on to complicating it. Substances come in different levels of organization, that is, simple and complex (or compounds) - this is the very first division into classes of substances, chemistry has many subsequent divisions, detailed and more complex. This classification, unlike many others, has strictly defined boundaries, each connection can be clearly attributed to one of the mutually exclusive species.
A simple substance in chemistry is a compound consisting of atoms of only one element from the periodic table of Mendeleev. As a rule, these are binary molecules, that is, consisting of two particles connected by a covalent non-polar bond - the formation of a common lone electron pair. So, atoms of the same chemical element have identical electronegativity, that is, the ability to hold a common electron density, so it is not shifted to any of the bond participants. Examples of simple substances (non-metals) are hydrogen and oxygen, chlorine, iodine, fluorine, nitrogen, sulfur, etc. A molecule of such a substance as ozone consists of three atoms, and all noble gases (argon, xenon, helium, etc.) consist of one. In metals (magnesium, calcium, copper, etc.) there is its own type of bond - metallic, which is carried out due to the socialization of free electrons inside the metal, and the formation of molecules as such is not observed. When recording a metal substance, simply the symbol of the chemical element is indicated without any indices.
A simple substance in chemistry, examples of which were given above, differs from a complex one in its qualitative composition. Chemical compounds are formed by atoms of different elements, from two or more. In such substances, covalent polar or ionic type of binding takes place. Since different atoms have different electronegativity, when a common electron pair is formed, it shifts towards a more electronegative element, which leads to a common polarization of the molecule. The ionic type is an extreme case of the polar one, when a pair of electrons completely passes to one of the binding participants, then the atoms (or groups of them) turn into ions. There is no clear boundary between these types, the ionic bond can be interpreted as a covalent strongly polar. Examples of complex substances are water, sand, glass, salts, oxides, etc.
Substance Modifications
Substances that are called simple actually have a unique feature that is not inherent in complex ones. Some chemical elements can form several forms of a simple substance. The basis is still one element, but the quantitative composition, structure and properties radically distinguish such formations. This feature is called allotropy.
Oxygen, sulfur, carbon and other elements have several For oxygen - this is O 2 and O 3, carbon gives four types of substances - carbine, diamond, graphite and fullerenes, the sulfur molecule can be rhombic, monoclinic and plastic modification. Such a simple substance in chemistry, examples of which are not limited to those listed above, is of great importance. In particular, fullerenes are used as semiconductors in engineering, photoresistors, additives for the growth of diamond films and for other purposes, and in medicine they are the most powerful antioxidants.
What happens to substances?
Every second there is a transformation of substances inside and around. Chemistry considers and explains those processes that go with a qualitative and / or quantitative change in the composition of the reacting molecules. In parallel, often interconnected, physical transformations also occur, which are characterized only by a change in the shape, color of substances or the state of aggregation, and some other characteristics.
Chemical phenomena are interaction reactions of various types, for example, compounds, substitutions, exchanges, decompositions, reversible, exothermic, redox, etc., depending on the change in the parameter of interest. These include: evaporation, condensation, sublimation, dissolution, freezing, electrical conductivity, etc. Often they accompany each other, for example, lightning during a thunderstorm is a physical process, and the release of ozone under its action is a chemical one.
Physical properties
In chemistry, a substance is matter that has certain physical properties. By their presence, absence, degree and intensity, one can predict how a substance will behave in certain conditions, as well as explain some chemical features of compounds. So, for example, high boiling points of organic compounds that contain hydrogen and an electronegative heteroatom (nitrogen, oxygen, etc.) indicate that such a chemical type of interaction as a hydrogen bond is manifested in a substance. Thanks to the knowledge of which substances have the best ability to conduct electric current, cables and wires of electrical wiring are made from certain metals.
Chemical properties
Chemistry is engaged in the establishment, research and study of the other side of the coin of properties. from her point of view, this is their reactivity to interaction. Some substances are extremely active in this sense, for example, metals or any oxidizing agents, while others, noble (inert) gases, practically do not enter into reactions under normal conditions. Chemical properties can be activated or passivated as needed, sometimes without much difficulty, and in some cases not easily. Scientists spend many hours in laboratories, by trial and error, achieving their goals, sometimes they do not achieve them. By changing the environmental parameters (temperature, pressure, etc.) or using special compounds - catalysts or inhibitors - it is possible to influence the chemical properties of substances, and hence the course of the reaction.
Classification of chemicals
All classifications are based on the division of compounds into organic and inorganic. The main element of organics is carbon, connecting with each other and hydrogen, carbon atoms form a hydrocarbon skeleton, which is then filled with other atoms (oxygen, nitrogen, phosphorus, sulfur, halogens, metals and others), closes in cycles or branches, thereby justifying a wide variety of organic compounds. To date, 20 million such substances are known to science. While there are only half a million mineral compounds.
Each compound is individual, but it also has many similar features with others in properties, structure and composition, on this basis there is a grouping into classes of substances. Chemistry has a high level of systematization and organization; it is an exact science.
inorganic substances
1. Oxides - binary compounds with oxygen:
a) acidic - when interacting with water, they give acid;
b) basic - when interacting with water, they give a base.
2. Acids - substances consisting of one or more hydrogen protons and an acid residue.
3. Bases (alkalis) - consist of one or more hydroxyl groups and a metal atom:
a) amphoteric hydroxides - exhibit the properties of both acids and bases.
4. Salts - the result between an acid and an alkali (soluble base), consist of a metal atom and one or more acidic residues:
a) acid salts - the anion of the acid residue contains a proton, the result of incomplete dissociation of the acid;
b) basic salts - a hydroxyl group is associated with the metal, the result of incomplete dissociation of the base.
organic compounds
There are a great many classes of substances in organic matter, it is difficult to remember such a volume of information at once. The main thing is to know the basic divisions into aliphatic and cyclic compounds, carbocyclic and heterocyclic, saturated and unsaturated. Hydrocarbons also have many derivatives in which the hydrogen atom is replaced by halogen, oxygen, nitrogen and other atoms, as well as functional groups.
Substance in chemistry is the basis of existence. Thanks to organic synthesis, a person today has a huge amount of artificial substances that replace natural ones, and also have no analogues in their characteristics in nature.
