How to pronounce the elements of the periodic table. Alphabetical list of chemical elements

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See also: List of chemical elements by symbol and Alphabetical list of chemical elements This is a list of chemical elements arranged in order of increasing atomic number. The table shows the name of the element, symbol, group and period in... ... Wikipedia

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The simplest form of matter that can be identified by chemical methods. These are components of simple and complex substances, representing a collection of atoms with the same nuclear charge. The charge of the nucleus of an atom is determined by the number of protons in... Collier's Encyclopedia

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Bess Ruff is a graduate student from Florida working toward a PhD in geography. She received her Master's degree in Environmental Science and Management from the Bren School of Environmental Science and Management at the University of California, Santa Barbara in 2016.

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If you find the periodic table difficult to understand, you are not alone! Although it can be difficult to understand its principles, learning how to use it will help you when studying science. First, study the structure of the table and what information you can learn from it about each chemical element. Then you can begin to study the properties of each element. And finally, using the periodic table, you can determine the number of neutrons in an atom of a particular chemical element.

Steps

Part 1

Table structure

The periodic table, or periodic table of chemical elements, begins in the upper left corner and ends at the end of the last row of the table (lower right corner). The elements in the table are arranged from left to right in increasing order of their atomic number. The atomic number shows how many protons are contained in one atom. In addition, as the atomic number increases, the atomic mass also increases. Thus, by the location of an element in the periodic table, its atomic mass can be determined.

As you can see, each subsequent element contains one more proton than the element preceding it. This is obvious when you look at the atomic numbers. Atomic numbers increase by one as you move from left to right. Because elements are arranged in groups, some table cells are left empty.
- For example, the first row of the table contains hydrogen, which has atomic number 1, and helium, which has atomic number 2. However, they are located on opposite edges because they belong to different groups.
Learn about groups that contain elements with similar physical and chemical properties. The elements of each group are located in the corresponding vertical column. They are typically identified by the same color, which helps identify elements with similar physical and chemical properties and predict their behavior. All elements of a particular group have the same number of electrons in their outer shell.
- Hydrogen can be classified as both alkali metals and halogens. In some tables it is indicated in both groups.
- In most cases, the groups are numbered from 1 to 18, and the numbers are placed at the top or bottom of the table. Numbers can be specified in Roman (eg IA) or Arabic (eg 1A or 1) numerals.
- When moving along a column from top to bottom, you are said to be “browsing a group.”
Find out why there are empty cells in the table. Elements are ordered not only according to their atomic number, but also by group (elements in the same group have similar physical and chemical properties). Thanks to this, it is easier to understand how a particular element behaves. However, as the atomic number increases, elements that fall into the corresponding group are not always found, so there are empty cells in the table.
- For example, the first 3 rows have empty cells because transition metals are only found from atomic number 21.
- Elements with atomic numbers 57 to 102 are classified as rare earth elements, and are usually placed in their own subgroup in the lower right corner of the table.
Each row of the table represents a period. All elements of the same period have the same number of atomic orbitals in which the electrons in the atoms are located. The number of orbitals corresponds to the period number. The table contains 7 rows, that is, 7 periods.
- For example, atoms of elements of the first period have one orbital, and atoms of elements of the seventh period have 7 orbitals.
- As a rule, periods are designated by numbers from 1 to 7 on the left of the table.
- As you move along a line from left to right, you are said to be “scanning the period.”
Learn to distinguish between metals, metalloids and non-metals. You will better understand the properties of an element if you can determine what type it is. For convenience, in most tables metals, metalloids, and nonmetals are designated by different colors. Metals are on the left and non-metals are on the right side of the table. Metalloids are located between them.

Part 2
Element designations
1. Each element is designated by one or two Latin letters. As a rule, the element symbol is shown in large letters in the center of the corresponding cell. A symbol is a shortened name for an element that is the same in most languages. Element symbols are commonly used when conducting experiments and working with chemical equations, so it is helpful to remember them.
  - Typically, element symbols are abbreviations of their Latin name, although for some, especially recently discovered elements, they are derived from the common name. For example, helium is represented by the symbol He, which is close to the common name in most languages. At the same time, iron is designated as Fe, which is an abbreviation of its Latin name.
2. Pay attention to the full name of the element if it is given in the table. This element "name" is used in regular texts. For example, "helium" and "carbon" are names of elements. Usually, although not always, the full names of the elements are listed below their chemical symbol.
  - Sometimes the table does not indicate the names of the elements and only gives their chemical symbols.
3. Find the atomic number. Typically, the atomic number of an element is located at the top of the corresponding cell, in the middle or in the corner. It may also appear under the element's symbol or name. Elements have atomic numbers from 1 to 118.
  - The atomic number is always an integer.
4. Remember that the atomic number corresponds to the number of protons in an atom. All atoms of an element contain the same number of protons. Unlike electrons, the number of protons in the atoms of an element remains constant. Otherwise, you would get a different chemical element!
  - The atomic number of an element can also determine the number of electrons and neutrons in an atom.
5. Usually the number of electrons is equal to the number of protons. The exception is the case when the atom is ionized. Protons have a positive charge and electrons have a negative charge. Because atoms are usually neutral, they contain the same number of electrons and protons. However, an atom can gain or lose electrons, in which case it becomes ionized.
  - Ions have an electrical charge. If an ion has more protons, it has a positive charge, in which case a plus sign is placed after the element symbol. If an ion contains more electrons, it has a negative charge, indicated by a minus sign.
  - The plus and minus signs are not used if the atom is not an ion.

“Chemical element - sulfur” - Natural intergrowth of native sulfur crystals. Molecules with closed (S4, S6) chains and open chains are possible. Sulfur ores are mined in different ways, depending on the conditions of occurrence. Natural sulfur minerals. We must not forget about the possibility of spontaneous combustion. Open pit mining of ore. Walking excavators remove layers of rock under which ore lies.

“Questions on chemical elements” - Can be stable and radioactive, natural and artificial. Associated with a change in the number of energy levels in the main subgroups. 8. Which element does not have a permanent “registration” in the Periodic Table? They are in constant motion. Tellurium, 2) selenium, 3) osmium, 4) germanium. Where does arsenic accumulate?

“H2O and H2S” - Sulfate ion. Y = ? K K2 =1.23 · 10?13 mol/l. Preparation: Na2SO3 + S = Na2SO3S (+t, aq. solution). In aqueous solution: +Hcl (ether). Vitriols MSO4·5(7)H2O (M – Cu, Fe, Ni, Mg…). Sulfuric acid H2SO4. Structure of SO32– and HSO3– anions. = y. The SO3 molecule is non-polar and diamagnetic. ? . Hydrosulfite ion: tautomerism.

“Periodic Table of Chemical Elements” - 8. How many electrons can be maximum in the third energy level? Arrange the elements in order of increasing metallic properties. Country name: "Chemical Elementary". Poems by Stepan Shchipachev. A. 17 B. 35 C. 35.5 D. 52 6. How many electrons rotate around the nucleus in a fluorine atom?

"Calcium Ca" - Ca compounds. Chemical properties of Ca. Physical properties of Ca. Calcium is one of the common elements. Application. Production of calcium in industry. Calcium Ca. Describe the physical properties of Ca. Being in nature. Revision task. Calcium Ca is a silvery white and fairly hard metal, lightweight.

“The element phosphorus” - Phosphorus is the 12th most abundant element in nature. Interaction with simple substances - non-metals. Interaction with metals. Quartz sand is added to bind calcium compounds. When white phosphorus is heated in an alkali solution, it disproportionates. Phosphorus. Black phosphorus.

There are a total of 46 presentations in the topic

Arsenic is a chemical element of the nitrogen group (group 15 of the periodic table). This is a gray, metallic, brittle substance (α-arsenic) with a rhombohedral crystal lattice. When heated to 600°C, As sublimates. When the vapor is cooled, a new modification appears - yellow arsenic. Above 270°C, all forms of As transform into black arsenic.

History of discovery

What arsenic was was known long before it was recognized as a chemical element. In the 4th century. BC e. Aristotle mentioned a substance called sandarac, which is now believed to have been realgar, or arsenic sulfide. And in the 1st century AD. e. the writers Pliny the Elder and Pedanius Dioscorides described orpiment - the dye As 2 S 3. In the 11th century n. e. There were three varieties of “arsenic”: white (As 4 O 6), yellow (As 2 S 3) and red (As 4 S 4). The element itself was probably first isolated in the 13th century by Albertus Magnus, who noted the appearance of a metal-like substance when arsenicum, another name for As 2 S 3, was heated with soap. But there is no certainty that this natural scientist obtained pure arsenic. The first authentic evidence of pure isolation dates back to 1649. German pharmacist Johann Schröder prepared arsenic by heating its oxide in the presence of coal. Later, Nicolas Lemery, a French physician and chemist, observed the formation of this chemical element by heating a mixture of its oxide, soap and potash. By the beginning of the 18th century, arsenic was already known as a unique semimetal.

Prevalence

In the earth's crust, the concentration of arsenic is low and amounts to 1.5 ppm. It is found in soil and minerals and can be released into the air, water and soil through wind and water erosion. In addition, the element enters the atmosphere from other sources. As a result of volcanic eruptions, about 3 thousand tons of arsenic are released into the air per year, microorganisms produce 20 thousand tons of volatile methylarsine per year, and as a result of the combustion of fossil fuels, 80 thousand tons are released over the same period.

Despite the fact that As is a deadly poison, it is an important component of the diet of some animals and, possibly, humans, although the required dose does not exceed 0.01 mg/day.

Arsenic is extremely difficult to convert into a water-soluble or volatile state. The fact that it is quite mobile means that large concentrations of the substance cannot appear in any one place. On the one hand, this is a good thing, but on the other hand, the ease with which it spreads is why arsenic contamination is becoming a bigger problem. Due to human activity, mainly through mining and smelting, the normally immobile chemical element migrates and can now be found in places other than its natural concentration.

The amount of arsenic in the earth's crust is about 5 g per ton. In space, its concentration is estimated to be 4 atoms per million silicon atoms. This element is widespread. A small amount of it is present in the native state. As a rule, arsenic formations with a purity of 90-98% are found together with metals such as antimony and silver. Most of it, however, is included in more than 150 different minerals - sulfides, arsenides, sulfoarsenides and arsenites. Arsenopyrite FeAsS is one of the most common As-containing minerals. Other common arsenic compounds are the minerals realgar As 4 S 4, orpiment As 2 S 3, lellingite FeAs 2 and enargite Cu 3 AsS 4. Arsenic oxide is also common. Most of this substance is a by-product of the smelting of copper, lead, cobalt and gold ores.

In nature, there is only one stable isotope of arsenic - 75 As. Among the artificial radioactive isotopes, 76 As with a half-life of 26.4 hours stands out. Arsenic-72, -74 and -76 are used in medical diagnostics.

Industrial production and application

Metallic arsenic is obtained by heating arsenopyrite to 650-700 °C without air access. If arsenopyrite and other metal ores are heated with oxygen, then As easily combines with it, forming easily sublimated As 4 O 6, also known as “white arsenic”. The oxide vapor is collected and condensed, and later purified by repeated sublimation. Most As is produced by its reduction with carbon from white arsenic thus obtained.

Global consumption of arsenic metal is relatively small - only a few hundred tons per year. Most of what is consumed comes from Sweden. It is used in metallurgy due to its metalloid properties. About 1% arsenic is used in the production of lead shot as it improves the roundness of the molten drop. The properties of lead-based bearing alloys improve both thermally and mechanically when they contain about 3% arsenic. The presence of small amounts of this chemical element in lead alloys hardens them for use in batteries and cable armor. Small arsenic impurities increase the corrosion resistance and thermal properties of copper and brass. In its pure form, the chemical elemental As is used for bronze coating and in pyrotechnics. Highly purified arsenic has applications in semiconductor technology, where it is used with silicon and germanium, and in the form of gallium arsenide (GaAs) in diodes, lasers and transistors.

As connections

Since the valency of arsenic is 3 and 5, and it has a range of oxidation states from -3 to +5, the element can form different types of compounds. Its most important commercially important forms are As 4 O 6 and As 2 O 5 . Arsenic oxide, commonly known as white arsenic, is a byproduct of roasting ores of copper, lead and some other metals, as well as arsenopyrite and sulfide ores. It is the starting material for most other compounds. It is also used in pesticides, as a decolorizing agent in glass production, and as a preservative for leathers. Arsenic pentoxide is formed when white arsenic is exposed to an oxidizing agent (such as nitric acid). It is the main ingredient in insecticides, herbicides and metal adhesives.

Arsine (AsH 3), a colorless poisonous gas composed of arsenic and hydrogen, is another known substance. The substance, also called arsenic hydrogen, is obtained by hydrolysis of metal arsenides and reduction of metals from arsenic compounds in acid solutions. It has found use as a dopant in semiconductors and as a chemical warfare agent. In agriculture, arsenic acid (H 3 AsO 4), lead arsenate (PbHAsO 4) and calcium arsenate [Ca 3 (AsO 4) 2], which are used for soil sterilization and pest control, are of great importance.

Arsenic is a chemical element that forms many organic compounds. Cacodyne (CH 3) 2 As−As(CH 3) 2, for example, is used in the preparation of the widely used desiccant (drying agent) cacodylic acid. Complex organic compounds of the element are used in the treatment of certain diseases, for example, amoebic dysentery caused by microorganisms.

Physical properties

What is arsenic in terms of its physical properties? In its most stable state, it is a brittle, steel-gray solid with low thermal and electrical conductivity. Although some forms of As are metal-like, classifying it as a nonmetal is a more accurate characterization of arsenic. There are other forms of arsenic, but they are not very well studied, especially the yellow metastable form, consisting of As 4 molecules, like white phosphorus P 4 . Arsenic sublimes at a temperature of 613 °C, and in the form of vapor it exists as As 4 molecules, which do not dissociate until a temperature of about 800 °C. Complete dissociation into As 2 molecules occurs at 1700 °C.

Atomic structure and ability to form bonds

The electronic formula of arsenic - 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 3 - resembles nitrogen and phosphorus in that there are five electrons in the outer shell, but it differs from them in having 18 electrons in the penultimate shell instead of two or eight. Adding 10 positive charges to the nucleus while filling the five 3d orbitals often causes an overall decrease in the electron cloud and an increase in the electronegativity of the elements. Arsenic in the periodic table can be compared with other groups that clearly demonstrate this pattern. For example, it is generally accepted that zinc is more electronegative than magnesium, and gallium than aluminum. However, in subsequent groups this difference decreases, and many do not agree that germanium is more electronegative than silicon, despite the abundance of chemical evidence. A similar transition from the 8- to 18-element shell from phosphorus to arsenic may increase electronegativity, but this remains controversial.

The similarity of the outer shell of As and P suggests that they can form 3 per atom in the presence of an additional unbonded electron pair. The oxidation state must therefore be +3 or -3, depending on the relative mutual electronegativity. The structure of arsenic also suggests the possibility of using the outer d-orbital to expand the octet, which allows the element to form 5 bonds. It is realized only when reacting with fluorine. The presence of a free electron pair for the formation of complex compounds (through electron donation) in the As atom is much less pronounced than in phosphorus and nitrogen.

Arsenic is stable in dry air, but turns into a black oxide in humid air. Its vapors burn easily, forming As 2 O 3. What is free arsenic? It is practically unaffected by water, alkalis and non-oxidizing acids, but is oxidized by nitric acid to a state of +5. Halogens and sulfur react with arsenic, and many metals form arsenides.

Analytical chemistry

The substance arsenic can be qualitatively detected in the form of yellow orpiment, which precipitates under the influence of a 25% solution of hydrochloric acid. Traces of As are typically determined by converting it to arsine, which can be detected using the Marsh test. Arsine thermally decomposes to form a black mirror of arsenic inside a narrow tube. According to the Gutzeit method, a sample impregnated with arsine darkens due to the release of mercury.

Toxicological characteristics of arsenic

The toxicity of the element and its derivatives varies widely, from the extremely toxic arsine and its organic derivatives to simply As, which is relatively inert. What arsenic is is evidenced by the use of its organic compounds as chemical warfare agents (lewisite), vesicant and defoliant (Agent Blue based on an aqueous mixture of 5% cacodylic acid and 26% of its sodium salt).

In general, derivatives of this chemical element irritate the skin and cause dermatitis. Protection from inhalation of arsenic-containing dust is also recommended, but most poisoning occurs through ingestion. The maximum permissible concentration of As in dust over an eight-hour working day is 0.5 mg/m 3 . For arsine, the dose is reduced to 0.05 ppm. In addition to the use of compounds of this chemical element as herbicides and pesticides, the use of arsenic in pharmacology made it possible to obtain salvarsan, the first successful drug against syphilis.

Health effects

Arsenic is one of the most toxic elements. Inorganic compounds of this chemical occur naturally in small quantities. People can be exposed to arsenic through food, water, and air. Exposure may also occur through skin contact with contaminated soil or water.

People who work with it, live in homes built from wood treated with it, and on agricultural lands where pesticides have been used in the past are also susceptible to exposure.

Inorganic arsenic can cause a variety of health effects in humans, such as stomach and intestinal irritation, decreased production of red and white blood cells, skin changes, and lung irritation. It is suspected that ingesting significant amounts of this substance may increase the chances of developing cancer, especially cancer of the skin, lungs, liver and lymphatic system.

Very high concentrations of inorganic arsenic cause infertility and miscarriages in women, dermatitis, decreased body resistance to infections, heart problems and brain damage. In addition, this chemical element can damage DNA.

The lethal dose of white arsenic is 100 mg.

Organic compounds of the element do not cause cancer or damage to the genetic code, but high doses can harm human health, for example, cause nervous disorders or abdominal pain.

Properties As

The main chemical and physical properties of arsenic are as follows:

Atomic number is 33.
Atomic weight - 74.9216.
The melting point of the gray form is 814 °C at a pressure of 36 atmospheres.
The density of the gray form is 5.73 g/cm 3 at 14 °C.
The density of the yellow form is 2.03 g/cm 3 at 18 °C.
The electronic formula of arsenic is 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 3.
Oxidation states - -3, +3, +5.
The valency of arsenic is 3.5.

All names of chemical elements come from Latin. This is necessary, first of all, so that scientists from different countries can understand each other.

Chemical symbols of elements

Elements are usually designated by chemical signs (symbols). According to the proposal of the Swedish chemist Berzelius (1813), chemical elements are designated by the initial or initial and one of the subsequent letters of the Latin name of a given element; The first letter is always uppercase, the second lowercase. For example, hydrogen (Hydrogenium) is designated by the letter H, oxygen (Oxygenium) by the letter O, sulfur (Sulfur) by the letter S; mercury (Hydrargyrum) - letters Hg, aluminum (Aluminium) - Al, iron (Ferrum) - Fe, etc.

Rice. 1. Table of chemical elements with names in Latin and Russian.

Russian names of chemical elements are often Latin names with modified endings. But there are also many elements whose pronunciation differs from the Latin source. These are either native Russian words (for example, iron), or words that are translations (for example, oxygen).

Chemical nomenclature

Chemical nomenclature is the correct name for chemical substances. The Latin word nomenclatura translates as “list of names”

At the early stage of the development of chemistry, substances were given arbitrary, random names (trivial names). Highly volatile liquids were called alcohols, these included “hydrochloric alcohol” - an aqueous solution of hydrochloric acid, “silitry alcohol” - nitric acid, “ammonium alcohol” - an aqueous solution of ammonia. Oily liquids and solids were called oils, for example, concentrated sulfuric acid was called “oil of vitriol,” and arsenic chloride was called “arsenic oil.”

Sometimes substances were named after their discoverer, for example, “Glauber’s salt” Na 2 SO 4 * 10H 2 O, discovered by the German chemist I. R. Glauber in the 17th century.

Rice. 2. Portrait of I. R. Glauber.

Ancient names could indicate the taste of substances, color, smell, appearance, and medical effect. One substance sometimes had several names.

By the end of the 18th century, chemists knew no more than 150-200 compounds.

The first system of scientific names in chemistry was developed in 1787 by a commission of chemists headed by A. Lavoisier. Lavoisier's chemical nomenclature served as the basis for the creation of national chemical nomenclatures. In order for chemists from different countries to understand each other, the nomenclature must be uniform. Currently, the construction of chemical formulas and names of inorganic substances is subject to a system of nomenclature rules created by a commission of the International Union of Pure and Applied Chemistry (IUPAC). Each substance is represented by a formula, in accordance with which the systematic name of the compound is constructed.

Rice. 3. A. Lavoisier.

What have we learned?

All chemical elements have Latin roots. Latin names of chemical elements are generally accepted. They are transferred into Russian using tracing or translation. however, some words have an original Russian meaning, for example, copper or iron. All chemical substances consisting of atoms and molecules are subject to chemical nomenclature. The system of scientific names was first developed by A. Lavoisier.