An atom is the smallest particle of a chemical that can preserve its properties. The word "atom" comes from the ancient Greek "atomos", which means "indivisible". Depending on how many and which particles are in an atom, a chemical element can be determined .
Briefly about the structure of the atom
How can we briefly list the basic information about the structure of an atom? An atom is a single-nucleus particle that is positively charged. Around this nucleus is a negatively charged cloud of electrons. Each atom in its normal state is neutral. The size of this particle can be completely determined by the size of the electron cloud that surrounds the core.
The nucleus itself, in turn, also consists of smaller particles - protons and neutrons. Protons are positively charged. Neutrons do not carry any charge. However, protons together with neutrons are combined into one category and are called nucleons. If basic information about the structure of the atom is needed briefly, then this information may be limited to the listed data .
The first information about the atom
The fact that matter can consist of small particles was suspected by the ancient Greeks. They believed that everything exists and consists of atoms. However, this view was purely philosophical in nature and cannot be interpreted scientifically.
The first basic information about the structure of the atom was received by the English scientist John Dalton. It was this researcher who was able to discover that two chemical elements can enter into different ratios, and each such combination will be a new substance. For example, eight parts of an oxygen element generate carbon dioxide. The four parts of oxygen are carbon monoxide.
In 1803, Dalton discovered the so-called law of multiple relations in chemistry. Using indirect measurements (since no atom could then be examined under the then microscopes), Dalton concluded the relative weight of the atoms .
Rutherford Research
Almost a century later, basic information about the structure of atoms was confirmed by another English chemist - Ernest Rutherford. The scientist proposed a model of the electron shell of the smallest particles.
At that time, the Rutherford-named “Planetary Atom Model” was one of the most important steps chemistry could take. Basic information about the structure of the atom indicated that it was similar to the solar system: electron particles revolve around strictly defined orbits around the nucleus, just like planets do.
The electron shell of atoms and the formulas of atoms of chemical elements
The electron shell of each of the atoms contains exactly as many electrons as there are protons in its nucleus. That is why the atom is neutral. In 1913, another scientist received basic information about the structure of the atom. The Niels Bohr formula was similar to the one that Rutherford received. According to his concept, electrons also revolve around a core located in the center. Bohr finalized Rutherford's theory, introduced harmony in its facts.
Already then the formulas of some chemicals were compiled. For example, the structure of the nitrogen atom is schematically denoted as 1s 2 2s 2 2p 3 , the structure of the sodium atom is expressed by the formula 1s 2 2s 2 2p 6 3s 1 . Through these formulas, you can see how many electrons move along each of the orbitals of a chemical substance.
Schrödinger Model
However, then this atomic model became obsolete. The basic information about the structure of the atom, known to science today, has largely become available thanks to the research of the Austrian physicist E. Schrödinger.
He proposed a new model of its structure - wave. By this time, scientists have already proved that the electron is endowed not only with the nature of the particle, but also has the properties of a wave.
However, the Schrödinger and Rutherford models also have general provisions. Their theories are similar in that electrons exist at certain levels.
Such levels are also called electron layers. Using the level number, the electron energy can be characterized. The higher the layer, the more energy it has. All levels are counted from the bottom up, so the level number corresponds to its energy. Each of the layers in the electron shell of an atom has its own sublevels. Moreover, the first level can have one sublevel, the second - two, the third - three, and so on (see the above electronic formulas of nitrogen and sodium).
Even smaller particles
At the moment, of course, even smaller particles are discovered than the electron, proton and neutron. It is known that a proton consists of quarks. There are even smaller particles of the universe - for example, a neutrino, which is one hundred times smaller than a quark and one billion times smaller than a proton.
A neutrino is such a small particle that it is 10 septillion times smaller than, for example, a tyrannosaurus. The tyrannosaurus itself is as many times smaller than the entire observable Universe.
Basic atomic structure: radioactivity
It has always been known that no chemical reaction can turn one element into another. But in the process of radioactive radiation, this happens spontaneously.
Radioactivity is the ability of atomic nuclei to transform into other nuclei - more stable. When people received basic information about the structure of atoms, isotopes to some extent could serve as the embodiment of the dreams of medieval alchemists.
During the decay of isotopes, radioactive radiation is emitted. Such a phenomenon was first discovered by Becquerel. The main form of radiation is alpha decay. With it, an alpha particle is released. There is also beta decay, in which a beta particle is ejected from the nucleus of an atom.
Natural and artificial isotopes
Currently, about 40 natural isotopes are known. Most of them are located in three categories: uranium-radium, thorium and sea anemone. All these isotopes can be found in nature - in rocks, soil, air. But besides them, it is also known about a thousand artificially derived isotopes that are obtained in nuclear reactors. Many of these isotopes are used in medicine, especially in diagnostics .
Proportions within an atom
If you imagine an atom whose dimensions will be comparable to the dimensions of an international sports stadium, then you can visually obtain the following proportions. Electrons of an atom in such a "stadium" will be located at the very top of the stands. Each of them will be smaller than the pin head. Then the core will be located in the center of this field, and its size will be no larger than the size of a pea.
Sometimes people ask how the atom actually looks. In fact, in the literal sense of the word, it does not look in any way - not for the reason that insufficiently good microscopes are used in science. The dimensions of the atom are in those areas where the concept of “visibility” simply does not exist.
Atoms are very small. But how small are these dimensions in reality? The fact is that the smallest salt particle, barely visible to the human eye, contains about one quintillion atoms.
If you imagine an atom of such a size that could fit in the human hand, then next to it would be viruses of 300-meter length. Bacteria would be 3 km long, and the thickness of a human hair would become 150 km. In a lying position, he could go beyond the boundaries of the earth's atmosphere. And if such proportions were valid, then human hair in length could reach the moon. Here it is such a complicated and interesting atom, the study of which scientists continue to do to this day.