We were taught at school to divide the periodic table diagonally with a ruler, starting with Bor and ending with Astatine, these were the territories of metals and non-metals. Everything above silicon and boron are non-metals.
Personally, I use such a table of periodic elements.
If in the old (abbreviated) version periodic table draw a straight line from the left upper corner to the bottom right, then most non-metals will be at the top. Although not all. And there are also semimetals, for example, arsenic and selenium. It is easier to say which elements are non-metals, because there are significantly fewer of them than metals. And all of them are usually highlighted in yellow as p-elements (although some metals get there). In the modern (long) version of the table, with 18 groups, all non-metals (except hydrogen) are on the right. These are all gases, halogens, as well as boron, carbon, silicon, phosphorus and sulfur. Not so much.
I remember how at school the teacher divided the periodic table with a ruler and showed us the territories of metals and non-metals. The periodic table is divided into two zones diagonally. Everything above silicon and boron are non-metals. Also in the new tables, these two groups are marked with different colors.
The periodic table of Mendeleev is more informative than it might seem at first glance. In it, you can find out about the element, whether it is a metal or a non-metal. To do this, you need to be able to visually divide the table into two parts:
What is under the red line are metals, the rest of the elements are non-metals.
How to recognize metal or not metal, metal is always in a solid state, except for mercury, and non-metal can be in any form, soft, solid, liquid, and so on. You can also determine by color, as it has already become clear metal, metallic color. How to determine it in the periodic table, for this you need to draw a diagonal line from boron to astatine, and all those elements that are above the line do not belong to the metal, but those that are below the line to the metal.
Metals in the table of D.I. Mendeleev are in all periods except the 1st (H and He), in all groups, in the side (B) subgroups there are only metals (d-elements). Non-metals are p-elements and are located only in the main (A) subgroups. There are 22 non-metal elements in total and they are arranged in steps, starting from the IIIA group, adding one element in each group: IIIA group - B - boron, 1UA group - C - carbon and Si - silicon; VA group - nitrogen (N), phosphorus - P, arsenic - As; V1A group (chalcogens) - oxygen (O), sulfur (S), selenium (Se), tellurium (Te), V11A group (halogens) - fluorine (F), chlorine (Cl), bromine (Br), iodine (I ), astatine (At); V111A group of inert or noble gases - helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Ra). Hydrogen is located in the first (A) and seventh (A) groups. If we mentally draw a diagonal from beryllium to bohrium, then non-metals are located above the diagonal in the main subgroups.
Especially for you and so that you can clearly understand how you can easily distinguish between metals and non-metals in the table, I give you the following diagram:
The red marker highlights the separating feature of metals from non-metals. Draw it on your plate and you will always know.
Over time, you simply remember all non-metals, especially since these elements are well known to everyone, and their number is small - only 22. But until you acquire such dexterity, remembering the method of separating metals from non-metals is very simple. The last two columns of the table are entirely devoted to non-metals - this is the extreme column of inert gases and the column of halogens, which begins with hydrogen. In the first two columns on the left, there are no non-metals at all - there are solid metals. Starting from the third group, non-metals appear in the columns - first one boron, then in the 4th group there are already two - carbon and silicon, in the 5th group - three - nitrogen, phosphorus and arsenic, in the 6th group of non-metals there are already 4 - oxygen, sulfur, selenium and tellurium, well, then follows the group of halogens, which was mentioned above. To facilitate the memorization of non-metals, such a convenient table is used where all non-metals are in a scarf:
Without memorization and the periodic table itself, remembering where the metal and where the non-metal is is unrealistic. But you can remember two simple rules. First rule - metallic properties decreases in a period from left to right. That is, those substances that stand at the beginning are metals, at the very end - non-metals. Just the first are alkali and alkaline earth metals, and then everything else, ending with inert gases. The second rule is that metallic properties increase from top to bottom in the group. For example, take the third group. We will not call boron metals, but under it is aluminum, which has pronounced metallic properties.
3 parts: Structure of the table Symbols of the elements Calculating the number of neutrons from atomic mass If the periodic table seems difficult for you to understand, you are not alone! Although it can be difficult to understand its principles, learning to work with it will help in the study of natural sciences. To get started, study the structure of the table and what information can be learned from it about each chemical element. Then you can start exploring 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.
How to determine from the periodic table where the metals are, and where ...
about metal and non-metallic properties substances, it is advisable to speak in connection with the periodic system of chemical elements. The periodic table establishes the dependence of the chemical properties of elements on their charge atomic nucleus. All elements… How to write chemical formulas
“Knowledge of fonts is one of the most elementary requirements for a detective!” – this is how the great Sherlock Holmes once instructed his friend and chronicler Dr. Watson. Similarly, we can boldly say, “Knowing how…
Table of groups of metals and non-metals in the periodic system ...
seasons; Times of Day; days of the week ... In the middle of the 19th century, D.I. Mendeleev noticed that Chemical properties elements also have certain sequence(they say that this idea came to him in a dream). The result of the miraculous dreams of the scientist was the Periodic Table of Chemical Elements, in which D.I. Mendeleev built chemical elements Ascending atomic mass. AT modern table chemical elements are arranged in ascending order of the element's atomic number (the number of protons in the nucleus of an atom).
Complete list of metals known to science
What are metals? Elements that lose electrons easily, are shiny (reflective), malleable (can be molded into other shapes), and are considered good conductors of heat and electricity are called metals. They are crucial to our way of life, as they are not only part of structures and technologies, but also essential to the production of almost all items. Metal is even in human body. When you look at a multivitamin's ingredient label, you'll see dozens of compounds listed.
Definition of metals and non-metals in the periodic table.
How to determine metal or non-metalIn the section Natural Sciences to the question of how to determine from the periodic table where is a metal and where is a non-metal? the best answer given by the Proscenium author is non-metals: H———————He ——B, C, N, O, F, Ne ———Si, P, S, Cl, Ar ————As, Se Br, Kr —————Te, I, Xe ——————-At, Rn The rest are metals
Nonmetals | Position in the periodic table
They are characterized by the properties of both metals and non-metals. Depending on the density, metals are divided into light (density 0.53 × 5 g/cm?) and heavy (5 × 22.5 g/cm?). Between metals and non-metals are semi-metals (metalloids). For example, in the IA(1) group, all elements from lithium (Li) to francium (Fr) donate one electron. In their "pure" form, these elements are, of course, metals and have all the properties of metals.
Table of groups of metals and non-metals in the periodic system of Mendeleev: what is it and how to determine the softest element
The Periodic Table of Chemical Elements was compiled by D. I. Mendeleev in the second half of the 19th century. What is it, and why is it needed? It combines all chemical elements in ascending order. atomic weight, and all of them are arranged so that their properties change periodically.
How to determine a metal or non-metal - how to determine by ...
Metals and non-metals in the periodic table — Article holding
Chemistry is one of the most ordered sciences. Although it has been known for a long time, the final proof was formulated by Mendeleev and expressed in the form of a periodic table. It was based on the atomic mass of the elements, modern scientists do this based on the number of protons and neutrons in the nucleus. One way or another, both options come down to the same scheme.
How to use the periodic table
Non-metals - elements from the 14th to the 16th groups of the periodic table. They almost do not conduct electricity and heat. Non-metals are very brittle and practically do not bend and any other deformations. They can exist in 2 out of 3 states of matter at room temperature: gas (e.g. oxygen) and solids(e.g. carbon). Non-metals, do not have a metallic luster and do not reflect light.
Metals and various non-metals in the periodic table of Mendeleev: signs and properties
Nature has a certain cyclicity and repetition in its manifestations. Ancient Greek scientists also paid attention to this when they tried to decompose the nature of things into components: elements, geometric figures and even atoms. Scientists of our time also pay attention to the signs of repetition. For example, Carl Linnaeus, based on phenotypic similarity, was able to build a system of living beings.
How to recognize metal or non-metal in the periodic table?
I know about “drawing a line from boron to astatine”. But here I have a problem: Fe, for example, is above the line, but it is a metal. Are there any exceptions or what? The second question are those elements that are on the line, they also have the properties of both metals and non-metals. Do they form a metallic bond?
Metals are the elements that make up the nature around us. As long as the Earth exists, so many metals exist.
The earth's crust contains the following metals:
- aluminum - 8.2%,
- iron - 4.1%,
- calcium - 4.1%,
- sodium - 2.3%,
- magnesium - 2.3%,
- potassium - 2.1%,
- titanium - 0.56%, etc.
On the this moment science has information about 118 chemical elements. Eighty-five of the elements on this list are metals.
Chemical properties of metals
In order to understand what the chemical properties of metals depend on, let's turn to an authoritative source - the table periodic system elements, so-called. periodic table. Let's draw a diagonal (you can mentally) between two points: start from Be (beryllium) and end at At (astatine). This division is, of course, arbitrary, but it still allows you to combine chemical elements in accordance with their properties. The elements to the left under the diagonal will be metals. The more to the left, relative to the diagonal, the location of the element, the more pronounced its metallic properties will be:
- crystal structure - dense,
- thermal conductivity - high,
- electrical conductivity decreasing with increasing temperature,
- level of the degree of ionization - low (electrons are separated freely)
- ability to form compounds (alloys),
- solubility (dissolve in strong acids and caustic alkalis),
- oxidizability (formation of oxides).
The above properties of metals depend on the presence of electrons freely moving in the crystal lattice. The elements located near the diagonal, or directly at the place of its passage, have dual signs of belonging, i.e. have the properties of metals and non-metals.
The radii of metal atoms are relatively big sizes. outer electrons, called valence, are significantly removed from the nucleus and, as a result, are weakly bound to it. Therefore, metal atoms easily donate valence electrons and form positively charged ions (cations). This feature is the main chemical property of metals. Atoms of elements with the most pronounced metallic properties on the outer energy level have one to three electrons. Chemical elements with characteristically pronounced signs of metals form only positively charged ions, they are not at all capable of attaching electrons.
Displacement series of M. V. Beketov
The activity of the metal and the reaction rate of its interaction with other substances depends on the value of the atom's ability to "part with electrons". The ability is expressed differently in different metals. Elements that have high rates, are active reducing agents. How more weight metal atom, the higher its restorative capacity. The strongest reducing agents are alkali metals K, Ca, Na. If the metal atoms are not able to donate electrons, then such an element will be considered an oxidizing agent, for example: cesium aurid can oxidize other metals. In this regard, alkali metal compounds are the most active.
The Russian scientist M. V. Beketov was the first to study the phenomenon of the displacement of some metals from the compounds formed by them, by other metals. The list of metals compiled by him, in which they are located in accordance with the degree of increase in normal potentials, was called the "electrochemical series of voltages" (Beketov's displacement series).
Li K Rb Cs Ca Na Mg Al Mn Zn Cr Cr Fe Ni Sn Pb Cu Hg Ag Pt Ag Pt Au
The more to the right the metal is located in this row, the lower it is. restorative properties, and the stronger oxidizing properties its ions.
Classification of metals according to Mendeleev
According to the periodic table, they differ the following types(subgroups) of metals:
- alkaline - Li (lithium), Na (sodium), K (potassium), Rb (rubidium), Cs (cesium), Fr (francium);
- alkaline earth - Be (beryllium), Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium), Ra (radium);
- light - AL (aluminum), In (indium), Cd (cadmium), Zn (zinc);
- transitional;
- semimetals
Technical application of metals
Metals that have found more or less widespread technical application, are conditionally divided into three groups: black, colored and noble.
To ferrous metals include iron and its alloys: steel, cast iron and ferroalloys.
It should be said that iron is the most common metal in nature. His chemical formula Fe (ferrum). Iron played huge role in human evolution. Man was able to obtain new tools of labor by learning to smelt iron. AT modern industry iron alloys are widely used, obtained by adding carbon or other metals to iron.
Non-ferrous metals - these are almost all metals with the exception of iron, its alloys and noble metals. According to their physical properties, non-ferrous metals are classified as follows:
· heavy metals: copper, nickel, lead, zinc, tin;
· lungs metals: aluminum, titanium, magnesium, beryllium, calcium, strontium, sodium, potassium, barium, lithium, rubidium, cesium;
· small metals: bismuth, cadmium, antimony, mercury, cobalt, arsenic;
· refractory metals: tungsten, molybdenum, vanadium, zirconium, niobium, tantalum, manganese, chromium;
· rare metals: gallium, germanium, indium, zirconium;
noble metals : gold, silver, platinum, rhodium, palladium, ruthenium, osmium.
It must be said that people got acquainted with gold much earlier than with iron. Gold jewelry from this metal was made back in Ancient Egypt. Nowadays, gold is also used in microelectronics and other industries.
Silver, like gold, is used in the jewelry industry, microelectronics, and the pharmaceutical industry.
Metals have accompanied man throughout history. human civilization. There is no industry where metals are not used. It is impossible to imagine modern life without metals and their compounds.
In nature, there are a lot of repeating sequences:
- seasons;
- Times of Day;
- days of the week…
In the middle of the 19th century, D.I. Mendeleev noticed that the chemical properties of elements also have a certain sequence (they say that this idea came to him in a dream). The result of the miraculous dreams of the scientist was the Periodic Table of Chemical Elements, in which D.I. Mendeleev arranged the chemical elements in order of increasing atomic mass. In the modern table, the chemical elements are arranged in ascending order of the atomic number of the element (the number of protons in the nucleus of an atom).
The atomic number is shown above the symbol of a chemical element, below the symbol is its atomic mass (the sum of protons and neutrons). Note that the atomic mass of some elements is a non-integer! Remember isotopes! Atomic mass is the weighted average of all the isotopes of an element that occur naturally under natural conditions.
Below the table are the lanthanides and actinides.
Metals, non-metals, metalloids
They are located in the Periodic Table to the left of the stepped diagonal line that starts with Boron (B) and ends with polonium (Po) (the exceptions are germanium (Ge) and antimony (Sb). It is easy to see that metals occupy most Periodic table. Basic properties of metals: solid (except mercury); glitter; good electrical and thermal conductors; plastic; malleable; donate electrons easily.
The elements to the right of the stepped diagonal B-Po are called non-metals. The properties of non-metals are directly opposite to the properties of metals: poor conductors of heat and electricity; fragile; non-forged; non-plastic; usually accept electrons.
Metalloids
Between metals and non-metals are semimetals(metalloids). They are characterized by the properties of both metals and non-metals. Semimetals have found their main industrial application in the production of semiconductors, without which no modern microcircuit or microprocessor is inconceivable.
Periods and groups
As mentioned above, the periodic table consists of seven periods. In each period, the atomic numbers of the elements increase from left to right.
The properties of elements in periods change sequentially: so sodium (Na) and magnesium (Mg), which are at the beginning of the third period, give up electrons (Na gives up one electron: 1s 2 2s 2 2p 6 3s 1; Mg gives up two electrons: 1s 2 2s 2 2p 6 3s 2). But chlorine (Cl), located at the end of the period, takes one element: 1s 2 2s 2 2p 6 3s 2 3p 5.
In groups, on the contrary, all elements have the same properties. For example, in the IA(1) group, all elements from lithium (Li) to francium (Fr) donate one electron. And all elements of group VIIA(17) take one element.
Some groups are so important that they have been given special names. These groups are discussed below.
Group IA(1). The atoms of the elements of this group have only one electron in the outer electron layer, so they easily donate one electron.
The most important alkali metals are sodium (Na) and potassium (K) as they play important role in the process of human life and are part of the salts.
Electronic configurations:
- Li- 1s 2 2s 1 ;
- Na- 1s 2 2s 2 2p 6 3s 1 ;
- K- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1
Group IIA(2). The atoms of the elements of this group have two electrons in the outer electron layer, which also give up during chemical reactions. Most important element- calcium (Ca) - the basis of bones and teeth.
Electronic configurations:
- Be- 1s 2 2s 2 ;
- mg- 1s 2 2s 2 2p 6 3s 2 ;
- Ca- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2
Group VIIA(17). Atoms of the elements of this group usually receive one electron each, because. on the outer electronic layer there are five elements each, and one electron is just missing to the "complete set".
The most famous elements of this group are: chlorine (Cl) - is part of salt and bleach; iodine (I) - an element that plays an important role in the activity thyroid gland person.
Electronic configuration:
- F- 1s 2 2s 2 2p 5 ;
- Cl- 1s 2 2s 2 2p 6 3s 2 3p 5 ;
- Br- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5
Group VIII(18). Atoms of the elements of this group have a fully "staffed" outer electron layer. Therefore, they "do not need" to accept electrons. And they don't want to give them away. Hence - the elements of this group are very "reluctant" to enter into chemical reactions. For a long time it was believed that they did not react at all (hence the name "inert", i.e. "inactive"). But chemist Neil Barlett discovered that some of these gases, under certain conditions, can still react with other elements.
Electronic configurations:
- Ne- 1s 2 2s 2 2p 6 ;
- Ar- 1s 2 2s 2 2p 6 3s 2 3p 6 ;
- kr- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6
Valence elements in groups
It is easy to see that within each group the elements are similar to each other in their valence electrons(electrons of s and p-orbitals located on the outer energy level).
Alkali metals have 1 valence electron each:
- Li- 1s 2 2s 1 ;
- Na- 1s 2 2s 2 2p 6 3s 1 ;
- K- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1
At alkaline earth metals- 2 valence electrons:
- Be- 1s 2 2s 2 ;
- mg- 1s 2 2s 2 2p 6 3s 2 ;
- Ca- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2
Halogens have 7 valence electrons:
- F- 1s 2 2s 2 2p 5 ;
- Cl- 1s 2 2s 2 2p 6 3s 2 3p 5 ;
- Br- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5
Inert gases have 8 valence electrons:
- Ne- 1s 2 2s 2 2p 6 ;
- Ar- 1s 2 2s 2 2p 6 3s 2 3p 6 ;
- kr- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6
For more information, see the article Valency and the Table of electronic configurations of atoms of chemical elements by periods.
Let us now turn our attention to the elements located in groups with symbols AT. They are located in the center of the periodic table and are called transition metals.
A distinctive feature of these elements is the presence of electrons in atoms that fill d-orbitals:
- sc- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 1 ;
- Ti- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2
Separate from the main table are located lanthanides and actinides are the so-called internal transition metals . In the atoms of these elements, electrons fill f-orbitals:
- Ce- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 4d 10 5s 2 5p 6 4f 1 5d 1 6s 2 ;
- Th- 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 4d 10 5s 2 5p 6 4f 14 5d 10 6s 2 6p 6 6d 2 7s 2
The properties of chemical elements allow them to be combined into appropriate groups. On this principle, a periodic system was created that changed the idea of existing substances and made it possible to assume the existence of new, previously unknown elements.
In contact with
Periodic system of Mendeleev
The Periodic Table of Chemical Elements was compiled by D. I. Mendeleev in the second half of the 19th century. What is it, and why is it needed? It combines all the chemical elements in order of increasing atomic weight, and all of them are arranged so that their properties change in a periodic manner.
Periodic system of Mendeleev brought into single system all existing elements, previously considered to be simply separate substances.
On the basis of its study, new chemical substances. The significance of this discovery for science cannot be overestimated., it was far ahead of its time and gave impetus to the development of chemistry for many decades.
There are three most common table options, which are conventionally referred to as "short", "long" and "extra long". ». The main table is considered to be a long table, it approved officially. The difference between them is the layout of the elements and the length of the periods.
What is a period
The system contains 7 periods. They are represented graphically as horizontal lines. In this case, the period can have one or two lines, called rows. Each subsequent element differs from the previous one by increasing the nuclear charge (the number of electrons) by one.
Put simply, a period is a horizontal row in the periodic table. Each of them begins with a metal and ends with an inert gas. Actually, this creates periodicity - the properties of elements change within one period, repeating again in the next. The first, second and third periods are incomplete, they are called small and contain 2, 8 and 8 elements, respectively. The rest are complete, they have 18 elements each.
What is a group
Group is a vertical column, containing elements with the same electronic structure or, to put it simply, with the same higher . The officially approved long table contains 18 groups that start with alkali metals and end with inert gases.
Each group has its own name, which makes it easier to find or classify elements. The metallic properties are enhanced regardless of the element in the direction from top to bottom. This is due to an increase in the number atomic orbits- the more of them, the weaker electronic communications, which makes the crystal lattice more pronounced.
Metals in the periodic table
Metals in the table Mendeleev have a predominant number, their list is quite extensive. They are characterized common features, according to their properties, they are heterogeneous and are divided into groups. Some of them have little in common with metals in physical sense, while others can exist only for fractions of a second and are absolutely not found in nature (according to at least, on the planet), because they were created, more precisely, calculated and confirmed in the laboratory, artificially. Each group has own signs
, the name is quite noticeably different from the others. This difference is especially pronounced in the first group.
The position of the metals
What is the position of metals in the periodic table? Elements are arranged by increasing atomic mass, or the number of electrons and protons. Their properties change periodically, so there is no neat one-to-one placement in the table. How to determine metals, and is it possible to do this according to the periodic table? In order to simplify the question, a special technique was invented: conditionally, at the places where the elements are connected, diagonal line from Bor to Polonius (or to Astatus). Those on the left are metals, those on the right are non-metals. It would be very simple and great, but there are exceptions - Germanium and Antimony.
Such a “method” is a kind of cheat sheet, it was invented only to simplify the memorization process. For a more accurate representation, remember that the list of non-metals is only 22 elements, therefore, answering the question of how many metals are contained in the periodic table
In the figure, you can clearly see which elements are non-metals and how they are arranged in the table by groups and periods.
General physical properties
There are general physical properties metals. These include:
- Plastic.
- characteristic brilliance.
- Electrical conductivity.
- High thermal conductivity.
- Everything except mercury is in a solid state.
It should be understood that the properties of metals vary greatly with respect to their chemical or physical essence. Some of them bear little resemblance to metals in the ordinary sense of the term. For example, mercury occupies a special position. She is at normal conditions is in liquid state, does not have crystal lattice, to the presence of which other metals owe their properties. The properties of the latter in this case are conditional, mercury is related to them in more chemical characteristics.
Interesting! Elements of the first group, alkali metals, in pure form do not occur, being part of various compounds.
The softest metal that exists in nature - cesium - belongs to this group. He, like other alkaline similar substances, has little in common with more typical metals. Some sources claim that in fact, the softest metal is potassium, which is difficult to dispute or confirm, since neither one nor the other element exists on its own - being released as a result of a chemical reaction, they quickly oxidize or react.
The second group of metals - alkaline earth - is much closer to the main groups. The name "alkaline earth" comes from ancient times, when oxides were called "earths" because they have a loose crumbly structure. More or less familiar (in the everyday sense) properties are possessed by metals starting from the 3rd group. As the group number increases, the amount of metals decreases.
