The difference between matter and field

The field, unlike substances, is characterized by continuity, the electromagnetic and gravitational fields, the field of nuclear forces, the wave fields of various elementary particles are known.

Modern natural science eliminates the difference between matter and field, considering that both substances and fields consist of various particles that have a corpuscular-wave (dual) nature. Revealing the close relationship between the field and matter led to a deepening of ideas about the unity of all forms and structure of the material world.

A homogeneous substance is characterized by density - the ratio of the mass of a substance to its volume:

where ρ - the density of the substance, m- the mass of the substance, V is the volume of the substance.

Physical fields do not have such a density.

Matter properties

Each substance has a set of specific properties - objective characteristics that determine the individuality of a particular substance and thus make it possible to distinguish it from all other substances. The most characteristic physicochemical properties include constants - density, melting point, boiling point, thermodynamic characteristics, parameters of the crystal structure. The main characteristics of a substance are its chemical properties.

Variety of substances

The number of substances is, in principle, infinitely large; to a known number of substances new substances are added all the time, both discovered in nature and synthesized artificially.

Individual substances and mixtures

Aggregate states

All substances, in principle, can exist in three states of aggregation - solid, liquid and gaseous. So, ice, liquid water and water vapor are solid, liquid and gaseous states of the same substance - water H 2 O. Solid, liquid and gaseous forms are not individual characteristics of substances, but only correspond to different ones, depending on external physical conditions states of existence of substances. Therefore, it is impossible to attribute to water only a sign of a liquid, to oxygen - a sign of a gas, and to sodium chloride - a sign of a solid state. Each of these (and all other substances) under changing conditions can go into any other of the three states of aggregation.

In the transition from ideal models of solid, liquid and gaseous states to real states of matter, several boundary intermediate types are found, the well-known of which are the amorphous (glassy) state, the state of a liquid crystal, and the highly elastic (polymeric) state. In this regard, the broader concept of "phase" is often used.

In physics, the fourth aggregate state of matter is considered - plasma, a partially or completely ionized state in which the density of positive and negative charges is the same (plasma is electrically neutral).

crystals

Crystals are solids that have a natural external shape of regular symmetrical polyhedra based on their internal structure, that is, on one of several certain regular arrangements of the particles (atoms, molecules, ions) that make up the substance. Crystal structure, being individual for each substance, refers to the basic physical and chemical properties. The particles that make up this solid form a crystal lattice. If the crystal lattices are stereometrically (spatially) the same or similar (have the same symmetry), then the geometric difference between them lies, in particular, in different distances between the particles occupying the lattice nodes. The distances between particles themselves are called lattice parameters. The lattice parameters, as well as the angles of geometric polyhedra, are determined by physical methods of structural analysis, for example, methods of X-ray structural analysis.

Often solids form (depending on conditions) more than one form of crystal lattice; such forms are called polymorphic modifications. For example, among simple substances, rhombic and monoclinic sulfur, graphite and diamond are known, which are hexagonal and cubic modifications of carbon, among complex substances - quartz, tridymite and cristobalite are various modifications of silicon dioxide.

organic matter

Literature

• Chemistry: Ref. ed. / W. Schroeter, K.-H. Lautenschleger, H. Bibrak and others: Per. with him. - M.: Chemistry, 1989

see also

Matter
Physics
quality characteristic	Substance hadronic matter neutron matter atomic substance

in its meaning is close to the concept of matter, but not completely equivalent to it. While the word "matter" is mainly associated with ideas about rough, inert, dead reality, in which exclusively mechanical laws dominate, substance is a "material", which, due to the receipt of a form, evokes thoughts about form, life suitability, ennoblement. See Gestalt weaving.

Great Definition

Incomplete definition ↓

Substance

by type of matter. A set of discrete formations with a rest mass.

The description "view" is morphological, correct, but it cannot satisfy us, since this is a purely classificatory division, to which, in reality, in the first approximation, nothing corresponds.

There is a hypothesis that matter in its "pure form" is vacuum (the first object). Then: substance is one of the objects (the fifth object) of the material world; matter in the form of a standing wave forms an elementary particle (electron, positron, proton, neutron, etc.) - the fourth object, in the form of a traveling wave - a photon (the third object), and their combination atom - substance. The second object is the field (vacuum stress, similar to the mechanical stress of a spring).

Here you can dream up: there is a vacuum (the first object) and something else (the zero object), for example, apeiron, the Universal Mind, God, etc., that is, something that is beyond the limits of perception from our World and whose interaction with vacuum gives field and matter, the further development (movement and transformation) of which creates the whole diversity of the World, including Life. This fantasy somewhat contradicts the system of views on the World, which is based on the concept of matter, as a thing "accessible to our observation."

Another option: matter, field and vacuum are different states of matter (similar to how water can be in different states: gas, liquid, solid).

Vacuum is an unperturbed state, field is a stressed state, matter is an oscillating state. Developing the idea further, we get: motionless matter - vacuum, a voltage wave moving in it - a field, a photon, a moving packet of standing waves - a substance.

Incomplete definition ↓

All chemicals can be divided into two types: pure substances and mixtures (Fig. 4.3).

Pure substances have a constant composition and well-defined chemical and physical properties. They are always homogeneous (uniform) in composition (see below). Pure substances, in turn, are divided into simple substances (free elements) and compounds.

A simple substance (free element) is a pure substance that cannot be divided into simpler pure substances. Elements are usually subdivided into metals and non-metals (see Chap. 11).

A compound is a pure substance consisting of two or more elements linked together in permanent and definite relationships. For example, the compound carbon dioxide (CO2) is made up of two elements, carbon and oxygen. Carbon dioxide consistently contains 27.37% carbon and 72.73% oxygen by mass. This statement applies equally to carbon dioxide samples taken at the North Pole, the South Pole, the Sahara Desert, or the Moon. Thus, in carbon dioxide, carbon and oxygen are always bound in a constant and strictly defined ratio.

Rice. 4.3. Classification of chemicals

Mixtures are substances composed of two or more pure substances. They have an arbitrary composition. In some cases, mixtures consist of one phase and are then called homogeneous (homogeneous). Solutions are an example of a homogeneous mixture. In other cases, mixtures consist of two or more phases. Then they are called heterogeneous (heterogeneous). Soil is an example of heterogeneous mixtures.

Types of particles. All chemicals - simple substances (elements), compounds or mixtures - are composed of particles of one of the three types that we have already met in previous chapters. These particles are:

• atoms (an atom consists of electrons, neutrons and protons, see Chapter 1; an atom of each element is characterized by a certain number of protons in its nucleus, and this number is called the atomic number of the corresponding element);
• molecules (a molecule consists of two or more atoms interconnected in an integer ratio);
• ions (an ion is an electrically charged atom or group of atoms; the charge of an ion is due to the addition or loss of electrons).

Elementary chemical particles. An elementary chemical particle is any chemically or isotopically individual atom, molecule, ion, radical, complex, etc., that can be identified as a separate species unit. A set of identical elementary chemical particles forms a chemical species. Chemical names, formulas and reaction equations can refer, depending on the context, either to elementary particles or to chemical species*. The concept of a chemical introduced above refers to a chemical species that can be obtained in sufficient quantity to allow detection of its chemical properties.

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. Also, hydrocarbons 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.