Tens of millions of chemical compounds are known, each of which is based on a relatively small number of particles. Let us find out how the views on the structure and composition of substances changed.

To know that “what is made of”

Ingots, jewelry, coins made of gold, silver, lumps of sulfur from volcanic sources, metallic iron and copper have been known for millennia. Ancient scholars tried to explain the structure. Democritus created atomistics, Aristotle became the "founding father" of modern science. Scientists have developed thoughts about materia prima in the form of five primary elements or elements: air, water, earth, fire and ether.

The ancient substance or substance was represented as “from which something is made”. There were ideas about the existence of very small particles - atoms. This term translated from Greek means "indivisible."

Substances - clusters of very small components

The study of particles is almost a detective story. The outstanding Russian scientist M. Lomonosov often used the words “corpuscle” “atom” and “molecule”. Everything was very confused: atoms are divisible or not, what does it consist of?

According to the decision of the International Congress of Chemists in 1860, an atom is the smallest particle that is part of a simple or complex substance. A molecule is a system of nuclei and electrons of two or more atoms. Particles invisible to the naked eye become visible only with a strong magnification of the electron microscope.

Atoms, isotopes

Atoms are made up of nuclei and electrons.The first are positively charged. Negatively charged electrons move near with great speed. Nuclei contain elementary particles: protons (positive), neutrons (negative).

If the number of protons is the same, and the number of neutrons is different, then such atoms of the same element have different masses and properties. They are isotopes. Hydrogen with one proton in the nucleus - protium - is the most common in the universe. Deuterium is a more massive isotope with one proton and one neutron in the nucleus. The legend of "living" and "dead" water probably came about due to the toxicity of heavy water containing deuterium.

The whole variety of inorganic substances, minerals, rocks, an abundance of organic compounds is due to:

• the identity of the particles of one substance;
• the presence of different structural units (atoms, molecules, ions);
• differences in charges, masses and sizes of types of atoms (chemical elements);
• the ability of atoms and molecules to lose or acquire electrons, turning into ions - charged particles;
• a huge number of electronic configurations, crystal structures;
• differences in the energy state of particles.

Interesting fact: Na, K, Ca, Cl atoms are life-threatening when they enter the body, Na +, K +, Ca2 +, Cl- ions are safe and vital for the body.

Features of the structure of substances

Substances can be molecular and ionic. Gaseous hydrogen, oxygen, carbon dioxide, nitrogen, chlorine, ammonia are composed of small molecules with a small mass.They have relatively low melting and boiling points.

Salts are predominantly ionic substances. Inert gases, diamond, graphite consist only of atoms. The peculiarity of the structure of metals is the presence of atoms, ions and "electron gas". Various chemically pure and highly pure substances are used in chemistry, the production of drugs and other products.

Interesting fact: knowledge of substances is of practical interest to ordinary people. You can save on the purchase of drugs. The price of original medicines includes marketing expenses (up to 90% of the cost of drugs). Generics are cheap analogues of the original drugs. They contain the same active substances, and the differences are in the production, components, volume of clinical trials.

Individual substances and mixtures

Distilled water is H2O molecules without impurities. Such a liquid is not used for drinking and cooking. Together with water, ions from the composition of soluble substances (electrolytes) must enter the human body. Natural, mineral, tap water contain, in addition to water molecules, metal ions, salts. Many of them are important for health.
Ions of macro- and microelements in products are erroneously called minerals. The latter are solid natural bodies, for example, quartz, flint, topaz. It is better to use the names "inorganic nutrients", "mineral additives."

Interesting fact: when there is a lack of a chemical element in the form of an ion or molecules in food, a person does not feel saturation.There is a subconscious desire to make up for the existing deficit due to other components of food, which often leads to metabolic disorders, obesity.

Around us are dominated by mixtures that contain two or more simple or complex substances. Atmospheric air is a mixture of gases. Residents of industrial areas, cities, in addition to gaseous oxygen, nitrogen and carbon dioxide, inhale the combustion products of all types of fuel, microparticles of lead, mercury and other heavy metals. The toxic effect of such a “cocktail” is much more dangerous than the harm of individual components.

The substances around and inside living organisms are diverse, composed of atoms, molecules, ions. There are few species of particles, but they create a great variety of simple and complex compounds. It is necessary to imagine, at least in general, what water, air, medicines, and food products consist of. Such knowledge gives advantages in life, helps to better navigate the world around us, to ensure our safety and survival.