Terms

What is the difference between physics and chemistry. Difference between physical chemistry and chemical physics. History of physical chemistry

Physics and chemistry are sciences that directly contribute to technological progress in the 21st century. Both disciplines study the laws of the functioning of the surrounding world, changes in the smallest particles of which it consists. All natural phenomena have a chemical or physical basis, this applies to everything: glow, burning, boiling, melting, any interaction of something with something.
Everyone at school studied the basics of chemistry and physics, biology and natural science, but not everyone connected their lives with these sciences, not everyone can determine the line between them now.

To understand what are the main differences between physical science and chemical science, you must first of all take a closer look at them and get acquainted with the main provisions of these disciplines.

About physics: movement and its laws

Physics deals direct study of the general properties of the surrounding world, simple and complex forms of motion of matter, natural phenomena that underlie all these processes. Science explores the qualities of various material objects and manifestations of interactions between them. Also under the gun of physicists are general patterns for different types of matter; these unifying principles are called physical laws.

Physics is in many ways a fundamental discipline, since it considers material systems at different scales most widely. It is in close contact with all natural sciences, the laws of physics determine both biological and geological phenomena to the same extent. There is a strong connection with mathematics, since all physical theories are formulated in terms of numbers and mathematical expressions. Roughly speaking, the discipline broadly studies absolutely all phenomena of the surrounding world and the patterns of their flow, based on the laws of physics.

Chemistry: what does everything consist of?

Chemistry is primarily concerned with the study of properties and substances in conjunction with their various changes. Chemical reactions are the results of mixing pure substances and creating new elements.

Science closely interacts with other natural disciplines such as biology, astronomy. Chemistry studies the internal composition of different types of matter, aspects of the interaction and transformation of the constituents of matter. Chemistry also uses its own laws and theories, regularities, scientific hypotheses.

What are the main differences between physics and chemistry?

Belonging to natural science unites these sciences in many ways, but there is much more difference between them than common:

The main difference between the two natural sciences is that physics studies elementary particles (the microworld, this includes the atomic and nucleon levels) and various properties of substances that are in a certain state of aggregation. Chemistry, on the other hand, is engaged in the study of the very processes of “assembling” molecules from atoms, the ability of a substance to enter into certain reactions with a substance of another kind.
Like biology and astronomy, modern physics allows for many non-rational concepts in its methodological tools, mainly theories of the origin of life on Earth, the origin of the Universe, connection with philosophy in considering the concepts of the primary cause of "ideal" and "material". Chemistry, however, remained much closer to the rational foundations of the exact sciences, moving away from both ancient alchemy and philosophy in general.
The chemical composition of bodies in physical phenomena remains unchanged, as well as their properties. Chemical phenomena provide for the transformation of a substance into another with the appearance of its new properties; this is the difference between the subjects studied by these disciplines.
A wide class of phenomena described by physics. Chemistry is much more highly specialized discipline, it focuses on the study of only the microcosm (molecular level), in contrast to physics (macrocosm and microcosm).
Physics deals with the study of material objects with their qualities and properties, while chemistry works with the composition of these objects, the smallest particles of which they are composed and which interact with each other.

Physical chemistry

"An Introduction to True Physical Chemistry". Manuscript of M. V. Lomonosov. 1752

Physical chemistry(often abbreviated in the literature as physical chemistry) - a section of chemistry, the science of the general laws of the structure, structure and transformation of chemicals. Explores chemical phenomena using theoretical and experimental methods of physics.

1History of Physical Chemistry

2Subject of Physical Chemistry

3 The difference between physical chemistry and chemical physics

4Sections of physical chemistry

o 4.1 Colloidal chemistry

o 4.2 Crystal chemistry

o 4.3 Radiochemistry

o 4.4 Thermochemistry

o 4.5The study of the structure of the atom

o 4.6 Corrosion of metals

o 4.7 Teaching about solutions

o 4.8 Chemical kinetics

o 4.9 Photochemistry

o 4.10 Chemical thermodynamics

o 4.11 Physical and chemical analysis

o 4.12 Theory of reactivity of chemical compounds

o 4.13 High energy chemistry

o 4.14 Laser chemistry

o 4.15 Radiation chemistry

o 4.16 Nuclear chemistry

o 4.17 Electrochemistry

o 4.18 Sound chemistry

o 4.19 Structural chemistry

5Potentiometry

History of physical chemistry[

The beginning of physical chemistry was laid in the middle of the 18th century. The term "Physical chemistry", in the modern understanding of the methodology of science and questions of the theory of knowledge, belongs to M. V. Lomonosov, who in 1752 read for the first time to students of St. Petersburg University "A Course in True Physical Chemistry". In the preamble to these lectures, he gives the following definition: "Physical chemistry is a science that must, on the basis of the provisions and experiments of physical scientists, explain the reason for what happens through chemical operations in complex bodies." The scientist in the works of his corpuscular-kinetic theory of heat deals with issues that fully meet the above tasks and methods. This is precisely the nature of the experimental actions that serve to confirm individual hypotheses and provisions of this concept. M. V. Lomonosov followed these principles in many areas of his research: in the development and practical implementation of the “science of glass” founded by him, in various experiments devoted to confirming the law of conservation of matter and force (motion); - in works and experiments related to the doctrine of solutions - he developed an extensive program of research on this physical and chemical phenomenon, which is in the process of development to the present day.

This was followed by a break of more than a hundred years, and D. I. Mendeleev began one of the first physicochemical studies in Russia in the late 1850s.

The next course in physical chemistry was taught by N. N. Beketov at Kharkov University in 1865.

The first in Russia Department of Physical Chemistry was opened in 1914 at the Faculty of Physics and Mathematics of St. Petersburg University, in the fall, a student of D.P. Konovalov, M.S. Vrevsky, began to read the compulsory course and practical classes in physical chemistry.

The first scientific journal intended to publish articles on physical chemistry was founded in 1887 by W. Ostwald and J. van't Hoff.

The subject of the study of physical chemistry[

Physical chemistry is the main theoretical foundation of modern chemistry, using the theoretical methods of such important sections of physics as quantum mechanics, statistical physics and thermodynamics, nonlinear dynamics, field theory, etc. It includes the study of the structure of matter, including: the structure of molecules, chemical thermodynamics, chemical kinetics and catalysis. Electrochemistry, photochemistry, the physical chemistry of surface phenomena (including adsorption), radiation chemistry, the study of metal corrosion, the physicochemistry of macromolecular compounds (see polymer physics), etc. are also distinguished as separate sections in physical chemistry. Very closely adjacent to physical chemistry and are sometimes considered as its independent sections - colloid chemistry, physico-chemical analysis and quantum chemistry. Most sections of physical chemistry have fairly clear boundaries in terms of objects and methods of research, in terms of methodological features and the apparatus used.

The difference between physical chemistry and chemical physics

Both of these sciences are at the interface between chemistry and physics, sometimes chemical physics is included in physical chemistry. It is not always possible to draw a clear line between these sciences. However, with a reasonable degree of accuracy, this difference can be determined as follows:

physical chemistry considers in total the processes occurring with the simultaneous participation sets particles;

chemical physics considers individual particles and the interaction between them, that is, specific atoms and molecules (thus, there is no place in it for the concept of "ideal gas", which is widely used in physical chemistry).

... to get worn out on the general topic of the words "physics" and "chemistry".

Isn't it surprising that both words are related to bodybuilding? "Physics" is muscles, "chemistry" - well, there is no need to explain it.

In general, the science of chemistry is, in principle, the same physics: about the phenomena occurring in nature. When Galileo threw balls from the Leaning Tower of Pisa, and Newton created his own laws, it was on a scale commensurate with man - this was and is physics. Ordinary physics deals with objects that are made up of substances. Chemistry (alchemy) was and is engaged in the transformation of substances into each other - this is the molecular level. It turns out that the difference between physics and chemistry is in the scale of objects? Nothing! Quantum physics deals with what atoms consist of - this is the submolecular level. Quantum physics deals with the objects within the atom, which gives power over atomic energy and raises philosophical questions. It turns out that chemistry is a narrow strip on the scale of physical scales, although it is clearly delimited by the level of the atomic-molecular structure of a substance.

I think that the bad flat (linear) infinity* does not apply to the surrounding world. Everything is looped or closed in a sphere. The universe is spherical. If we dig further into the structure of elementary particles (quarks and Higgs bosons), then sooner or later the found particles will close with the maximum scale - with the Universe, that is, sooner or later we will see our Universe from a bird's eye view in a microscope.

Now let's see if scale ranges apply to bodybuilding. It looks like yes. “Physics” (training with iron and on simulators) deals with iron objects and muscles as solid objects: a scale commensurate with a person. "Chemistry" (like steroids) is, of course, a molecular level. It remains to figure out what “quantum physics” is in bodybuilding? Apparently, this is motivation, concentration, willpower, and so on - that is, the psyche. And the psyche is based not on a molecular basis, but on certain electric fields and states - their scale is lower than the atomic one. So about (t) enough bodybuilding all scale ...

We read the article by Ph.D. Elena Gorokhovskaya(“Novaya Gazeta”, No. 55, May 24, 2013, p. 12 or on the Postnauka website) on the basics of biosemiotics:

What is living? (…) The main “watershed” runs between reductionist** and anti-reductionist approaches. Reductionists argue that life in all its specifics can be explained in terms of physical and chemical processes. Anti-reductionist approaches argue that everything cannot be reduced to physics and chemistry. The most difficult thing is to understand the integrity and expedient structure of a living organism, where everything is interconnected and everything is aimed at supporting its vital activity, reproduction and development. In the course of individual development, and indeed every moment in the body, something changes, while ensuring the regular course of these changes. It is often said that living organisms should be called not objects, but processes.
… In the 20th century, cybernetics became important for understanding the specifics of living things, since it rehabilitated the concept of purpose in biology. In addition, cybernetics has made the notion of living organisms as information systems very popular. Thus, in the science of the living, humanitarian ideas were actually introduced that were not directly related to the material organization.
In the 1960s, a new direction arose in understanding the specifics of the living and in the study of biological systems - biosemiotics, which considers life and living organisms as sign processes and relationships. We can say that living organisms do not live in the world of things, but in the world of meanings.
...Molecular genetics has been formed to a large extent due to the inclusion in its conceptual scheme of such concepts as "genetic information" and "genetic code". Speaking about the discovery of the genetic code, the famous biologist Martynas Ičas wrote: “The most difficult thing in the“ code problem ”was to understand that the code exists. It took a whole century."
Although the biosynthesis of proteins is carried out in the cell with the help of many chemical reactions, there is no direct chemical relationship between the structure of proteins and the structure of nucleic acids. This connection is inherently not chemical, but informational, semiotic in nature. The nucleotide sequences in the nucleic acids of DNA and RNA are information about the structure of proteins (about the amino acid sequences in them) only because there is a “reader” (aka “writer”) in the cell - in this case, a complex system of protein biosynthesis that owns the “genetic language." (...) Thus, even at the most fundamental level, the living turns out to be communication, text and "speech". Reading, writing, rewriting, creation of new texts and constant “conversation” in the language of the genetic code of macromolecules and their interactions are constantly taking place in each cell and in the body as a whole.

* * *

Let's replace a few words in the phrases from the first and last paragraphs:

Retrogrades argue that bodybuilding in all its specifics can be reduced to physical training and chemical exposure. The progressive approach asserts that one cannot reduce everything to "physics" and "chemistry". Although muscle mass growth is carried out through a variety of physical exercises and chemical (at least nutritional) influences, there is no direct relationship between muscle growth and the amount of exercise and the amount of "chemistry" does not exist. This connection is inherently not physical or chemical, but informational, semiotic in nature. Thus, even at the most fundamental level bodybuilding turns out to be communication, text and "speech"(this, of course, is not about vulgar chatter between approaches). Therefore, it can be said that bodybuilders should not be called objects, but informational processes.

Who would argue that you can’t build a muscle foolishly. We need a properly constructed and executed training, we need proper nutrition, that is, information is required. And if we foolishly stuff ourselves with chemistry, we will get an ambiguous result, if we get it at all. We need a properly constructed and executed course, that is, again, information is required. The most difficult thing about the problem of such information is to understand that it actually exists. And realizing this, one must learn to isolate it from that muddy pseudo-informational ocean that rolls on the shore of our brain in heavy waves, occasionally throwing pearl shells out of its depths.

True, to open the shells you need an oyster knife ...

------------
* bad infinity- a metaphysical understanding of the infinity of the world, involving the assumption of a monotonous, endlessly repeating alternation of the same specific properties, processes and laws of motion on any scale of space and time, without any limit. As applied to the structure of matter, it means the assumption of unlimited divisibility of matter, in which each smaller particle has the same properties and obeys the same specific laws of motion as macroscopic bodies. The term was introduced by Hegel, who, however, considered true infinity to be a property of the absolute spirit, but not of matter.
** reductionist approach- from the Latin reductio - return, restoration; in this case, the reduction of the phenomena of life to something else.

History of physical chemistry

M.V. Lomonosov, which in 1752

N.N. Beketov 1865

And Nernst.

M. S. VREVSKII

Molecules, ions, free radicals.

Atoms of elements can form three types of particles involved in chemical processes - molecules, ions and free radicals.

molecule called the smallest neutral particle of a substance that has its chemical properties and is capable of independent existence. There are monatomic and polyatomic molecules (two-, three-atomic, etc.). Under normal conditions, noble gases are composed of monatomic molecules; molecules of macromolecular compounds, on the contrary, contain many thousands of atoms.

And he- a charged particle, which is an atom or a group of chemically bonded atoms with an excess of electrons (anions) or a lack of them (cations). In matter, positive ions always exist together with negative ones. Since the electrostatic forces acting between the ions are large, it is impossible to create any significant excess of ions of the same sign in the substance.

free radical a particle is called that has unsaturated valences, i.e., a particle with unpaired electrons. Such particles are, for example ·CH 3 and ·NH 2 . Under normal conditions, free radicals, as a rule, cannot exist for a long time, since they are extremely reactive and easily react, forming inert particles. So, two methyl radicals CH3 are combined into a C 2 H 6 (ethane) molecule. The course of many reactions is impossible without the participation of free radicals. At very high temperatures (for example, in the atmosphere of the Sun), the only diatomic particles that can exist are free radicals (·CN, ·OH, ·CH and some others). Many free radicals are present in the flame.

Free radicals of a more complex structure are known, which are relatively stable and can exist under normal conditions, for example, the triphenylmethyl (C 6 H 5) 3 C radical (with its discovery, the study of free radicals began). One of the reasons for its stability are spatial factors - the large size of the phenyl groups, which prevent the combination of radicals into a hexaphenylethane molecule.

covalent bond.

Each chemical bond in structural formulas is represented valence line , For example:

H−H (bond between two hydrogen atoms)

H 3 N−H + (bond between the nitrogen atom of the ammonia molecule and the hydrogen cation)

(K +) - (I -) (bond between potassium cation and iodide ion).

A chemical bond is formed by attraction of atomic nuclei to a pair of electrons(indicated by dots ), which in the electronic formulas of complex particles (molecules, complex ions) is represented by valence line−, unlike their own, lone pairs of electrons each atom, for example:

:::F−F:::

(F2);

H−Cl:::

(HCl);

.. H−N−H | H

(NH3)

The chemical bond is called covalent if it is formed by socialization of a pair of electrons both atoms.

Polarity of molecules

Molecules that are formed by atoms of the same element tend to be non-polar , as the bonds themselves are non-polar. So, the molecules H 2, F 2, N 2 are non-polar.

Molecules that are formed by atoms of different elements can be polar and non-polar . It depends on the geometric shape.
If the shape is symmetrical, then the molecule non-polar(BF 3, CH 4, CO 2, SO 3), if asymmetric (due to the presence of lone pairs or unpaired electrons), then the molecule polar(NH 3, H 2 O, SO 2, NO 2).

When replacing one of the side atoms in a symmetric molecule with an atom of another element, the geometric shape is also distorted and polarity appears, for example, in the chlorine derivatives of methane CH 3 Cl, CH 2 Cl 2 and CHCl 3 (methane CH 4 molecules are nonpolar).

Polarity asymmetric in shape of a molecule follows from polarity of covalent bonds between the atoms of the elements with different electronegativity .
As noted above, there is a partial shift of the electron density along the bond axis to an atom of a more electronegative element, for example:

H δ+ → Cl δ−	B δ+ → F δ−
C δ− ← H δ+	N δ− ← H δ+

(here δ is the partial electric charge on the atoms).

The more electronegativity difference elements, the higher the absolute value of the charge δ and the more polar there will be a covalent bond.

In molecules that are symmetrical in shape (for example, BF 3), the "centers of gravity" of the negative (δ−) and positive (δ+) charges coincide, and in asymmetric molecules (for example, NH 3) they do not coincide.
As a result, in asymmetric molecules, electric dipole - Opposite charges separated by some distance in space, for example, in a water molecule.

Hydrogen bond.

In the study of many substances, the so-called hydrogen bonds . For example, HF molecules in liquid hydrogen fluoride are interconnected by a hydrogen bond, H 2 O molecules in liquid water or in an ice crystal, as well as NH 3 and H 2 O molecules are similarly connected to each other in an intermolecular compound - ammonia hydrate NH 3 H 2 O.

Hydrogen bonds unstable and are destroyed quite easily (for example, when ice melts, water boils). However, some additional energy is expended on breaking these bonds, and therefore the melting and boiling points of substances with hydrogen bonds between molecules turn out to be much higher than those of similar substances, but without hydrogen bonds:

Valence. Donor-acceptor bonds. According to the theory of molecular structure, atoms can form as many covalent bonds as they have orbitals occupied by one electron, but this is not always the case. [In the accepted AO filling scheme, first indicate the shell number, then the type of orbital, and then, if there is more than one electron in the orbital, their number (superscript). So, record (2 s) 2 means that on s-orbitals of the second shell are two electrons.] A carbon atom in the ground state (3 R) has an electronic configuration (1 s) 2 (2s) 2 (2p x)(2 p y), while two orbitals are not filled, i.e. contain one electron. However, divalent carbon compounds are very rare and have high chemical activity. Usually carbon is tetravalent, and this is due to the fact that for its transition to an excited 5 S-state (1 s) 2 (2s) (2p x)(2 p y)(2 p z) with four empty orbitals, very little energy is needed. Energy costs associated with transition 2 s-electron to free 2 R-orbital, are more than offset by the energy released during the formation of two additional bonds. For the formation of unfilled AO, it is necessary that this process be energetically favorable. Nitrogen atom with electronic configuration (1 s) 2 (2s) 2 (2p x)(2 p y)(2 p z) does not form pentavalent compounds, since the energy required for translation 2 s-electron by 3 d-orbital with the formation of a pentavalent configuration (1 s) 2 (2s)(2p x)(2 p y)(2 p z)(3 d) is too large. Similarly, boron atoms with the usual configuration (1 s) 2 (2s) 2 (2p) can form trivalent compounds while in an excited state (1 s) 2 (2s)(2p x)(2 p y) that occurs at the transition 2 s-electron by 2 R-AO, but does not form pentavalent compounds, since the transition to an excited state (1 s)(2s)(2p x)(2 p y)(2 p z) due to the translation of one of the 1 s-electrons to a higher level, requires too much energy. The interaction of atoms with the formation of a bond between them occurs only in the presence of orbitals with close energies, i.e. orbitals with the same principal quantum number. The relevant data for the first 10 elements of the periodic table are summarized below. The valence state of an atom is understood as the state in which it forms chemical bonds, for example, state 5 S for tetravalent carbon.

VALENCE STATES AND VALENCES OF THE FIRST TEN ELEMENTS OF THE PERIODIC TABLE
Element	Basic state	Normal valence state	Usual valence
H	(1s)	(1s)
He	(1s) 2	(1s) 2
Li	(1s) 2 (2s)	(1s) 2 (2s)
Be	(1s) 2 (2s) 2	(1s) 2 (2s)(2p)
B	(1s) 2 (2s) 2 (2p)	(1s) 2 (2s)(2p x)(2 p y)
C	(1s) 2 (2s) 2 (2p x)(2 p y)	(1s) 2 (2s)(2p x)(2 p y)(2 p z)
N	(1s) 2 (2s) 2 (2p x)(2 p y)(2 p z)	(1s) 2 (2s) 2 (2p x)(2 p y)(2 p z)
O	(1s) 2 (2s) 2 (2p x) 2 (2 p y)(2 p z)	(1s) 2 (2s) 2 (2p x) 2 (2 p y)(2 p z)
F	(1s) 2 (2s) 2 (2p x) 2 (2 p y) 2 (2 p z)	(1s) 2 (2s) 2 (2p x) 2 (2 p y) 2 (2 p z)
Ne	(1s) 2 (2s) 2 (2p x) 2 (2 p y) 2 (2 p z) 2	(1s) 2 (2s) 2 (2p x) 2 (2 p y) 2 (2 p z) 2

These patterns are shown in the following examples:

History of physical chemistry

The beginning of physical chemistry was laid in the middle of the 18th century. The term "Physical Chemistry" belongs to M.V. Lomonosov, which in 1752 In 1992, he first read to the students of St. Petersburg University the "Course of True Physical Chemistry". In this course, he himself gave this definition of this science: "Physical chemistry is a science that must, on the basis of the provisions and experiments of physical scientists, explain the reason for what happens through chemical operations in complex bodies."

This was followed by a break of more than a hundred years, and the next course in physical chemistry was read by Academician N.N. Beketov at Kharkiv University in 1865 year. Following N.N. Beketov began teaching physical chemistry at other universities in Russia. Flavitsky (Kazan, 1874), V. Ostwald (University in Tartu, 18807), I.A. Kablukov (Moscow University, 1886).

The recognition of physical chemistry as an independent science and academic discipline was expressed at the University of Leipzig (Germany) in 1887. The first department of physical chemistry headed by W. Ostwald and at the base of the first scientific journal on physical chemistry there. At the end of the 19th century, the University of Leipzig was the center for the development of physical chemistry, and the leading physical chemists were: W. Ostwald, J. van't Hoff, Arrhenius and Nernst.

The first department of physical chemistry in Russia was opened in 1914 at the Faculty of Physics and Mathematics of St. Petersburg University, where in the autumn he began to read a compulsory course and practical classes in physical chemistry M. S. VREVSKII

The difference between physical chemistry and chemical physics

physical chemistry considers in total the processes occurring with the simultaneous participation sets particles;

Lecture 2 The structure of molecules and the nature of the chemical bond. Types of chemical bonds. The concept of the electronegativity of an element. Polarization. dipole moment. Atomic energy of the formation of molecules. Methods for experimental study of the structure of molecules.

The structure of the molecules(molecular structure), the mutual arrangement of atoms in molecules. In the course of chemical reactions, the atoms in the molecules of the reactants are rearranged and new compounds are formed. Therefore, one of the fundamental chemical problems is to elucidate the arrangement of atoms in the initial compounds and the nature of the changes during the formation of other compounds from them.

The first ideas about the structure of molecules were based on the analysis of the chemical behavior of matter. These ideas became more complicated as knowledge about the chemical properties of substances accumulated. The application of the basic laws of chemistry made it possible to determine the number and type of atoms that make up the molecule of a given compound; this information is contained in the chemical formula. Over time, chemists realized that one chemical formula is not enough to accurately characterize a molecule, since there are isomer molecules that have the same chemical formulas, but different properties. This fact led scientists to the idea that the atoms in a molecule must have a certain topology, stabilized by the bonds between them. This idea was first expressed in 1858 by the German chemist F. Kekule. According to his ideas, a molecule can be depicted using a structural formula, which indicates not only the atoms themselves, but also the bonds between them. Interatomic bonds must also correspond to the spatial arrangement of atoms. The stages in the development of ideas about the structure of the methane molecule are shown in Figs. 1. Structure meets modern data G : the molecule has the shape of a regular tetrahedron, in the center of which is a carbon atom, and at the vertices are hydrogen atoms.

Such studies, however, did not say anything about the size of the molecules. This information became available only with the development of appropriate physical methods. The most important of these was X-ray diffraction. From the patterns of X-ray scattering on crystals, it became possible to determine the exact position of atoms in a crystal, and for molecular crystals, it was possible to localize atoms in a single molecule. Other methods include the diffraction of electrons as they pass through gases or vapors and the analysis of the rotational spectra of molecules.

All this information gives only a general idea of the structure of the molecule. The nature of chemical bonds can be explored by modern quantum theory. And although the molecular structure cannot yet be calculated with a sufficiently high accuracy, all known data on chemical bonds can be explained. The existence of new types of chemical bonds has even been predicted.

Often, from many people who discuss a particular process, you can hear the words: "This is physics!" or "It's chemistry!" Indeed, almost all phenomena in nature, in everyday life and in space, which a person encounters during his life, can be attributed to one of these sciences. It is interesting to understand how physical phenomena differ from chemical ones.

science physics

Before answering the question of how physical phenomena differ from chemical ones, it is necessary to understand what objects and processes each of these sciences investigates. Let's start with physics.

science chemistry

Unlike physics, chemistry is a science that studies the structure, composition and properties of matter, as well as its change as a result of chemical reactions. That is, the object of study of chemistry is the chemical composition and its change during a certain process.

Chemistry, like physics, has many branches, each of which studies a certain class of chemicals, for example, organic and inorganic, bio- and electrochemistry. Research in medicine, biology, geology and even astronomy is based on the achievements of this science.

It is interesting to note that chemistry, as a science, was not recognized by ancient Greek philosophers because of its focus on experiment, as well as because of the pseudoscientific knowledge that surrounded it (recall that modern chemistry was "born" from alchemy). Only since the Renaissance, and largely thanks to the work of the English chemist, physicist and philosopher Robert Boyle, chemistry began to be perceived as a full-fledged science.

Examples of physical phenomena

There are a huge number of examples that obey physical laws. For example, every student knows already in the 5th grade a physical phenomenon - the movement of a car along the road. At the same time, it does not matter what this car consists of, where it takes energy from to move, the only important thing is that it moves in space (along the road) along a certain trajectory at a certain speed. Moreover, the processes of acceleration and deceleration of the car are also physical. The section of physics "Mechanics" deals with the movement of a car and other solid bodies.