Metals: general characteristics of metals and alloys. General characteristics of metals Message on the topic of metals in chemistry

The properties of chemical elements make it possible to combine them into appropriate groups. On this principle, the periodic system was created, which changed the idea of ​​existing substances and made it possible to assume the existence of new, previously unknown elements.

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Mendeleev's periodic table

The periodic table of chemical elements was compiled by D.I. Mendeleev in the second half of the 19th century. What is it and what is it for? It unites all chemical elements in order of increasing atomic weight, and they are all arranged in such a way that their properties change in a periodic manner.

Mendeleev's periodic system brought together into a single system all existing elements, previously considered simply individual substances.

Based on its study, new chemical substances were predicted and subsequently synthesized. The significance of this discovery for science cannot be overestimated, it was significantly 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 called “short”, “long” and “extra-long” ». The main table is considered to be a long table, it officially approved. The difference between them is the arrangement of elements and the length of periods.

What is a period

The system contains 7 periods. They are presented graphically as horizontal lines. In this case, a period can have one or two lines, called rows. Each subsequent element differs from the previous one by increasing the nuclear charge (number of electrons) by one.

To keep it simple, a period is a horizontal row of the periodic table. Each of them begins with 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

A group is a vertical column, containing elements with the same electronic structure or, more simply, with the same higher value. The officially approved long table contains 18 groups, which begin with alkali metals and end with noble gases.

Each group has its own name, making it easier to search or classify elements. Metallic properties are enhanced, regardless of the element, from top to bottom. This is due to an increase in the number of atomic orbits - the more there are, the weaker the electronic bonds, 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 by common characteristics; they are heterogeneous in their properties and are divided into groups. Some of them have little in common with metals in the physical sense, while others can exist only for a fraction of a second and are absolutely not found in nature (at least on the planet), since they were created, or rather, calculated and confirmed in laboratory conditions, artificially. Each group has its own characteristics, the name is quite noticeably different from the others. This difference is especially pronounced in the first group.

Position of metals

What is the position of metals in the periodic table? Elements are arranged by increasing atomic mass, or number of electrons and protons. Their properties change periodically, so there is no neat placement on a one-to-one basis in the table. How to identify metals, and is it possible to do this using the periodic table? In order to simplify the question, a special technique was invented: conditionally, a diagonal line is drawn from Bor to Polonius (or to Astatus) at the junctions of the elements. Those on the left are metals, those on the right are non-metals. This would be very simple and cool, but there are exceptions - Germanium and Antimony.

This “methodology” is a kind of cheat sheet; it was invented only to simplify the memorization process. For a more accurate representation, it should be remembered that the list of nonmetals is only 22 elements, therefore, answering the question, 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 of metals. These include:

• Plastic.
• Characteristic shine.
• Electrical conductivity.
• High thermal conductivity.
• All except mercury are in a solid state.

It should be understood that the properties of metals vary greatly regarding 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. Under normal conditions, it is in a liquid state and does not have a crystal lattice, the presence of which other metals owe their properties to. The properties of the latter in this case are conditional; mercury is similar to them to a greater extent in its chemical characteristics.

Interesting! Elements of the first group, alkali metals, are not found in pure form, but are found in various compounds.

The softest metal existing in nature, cesium, belongs to this group. It, like other alkaline 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 - when released as a result of a chemical reaction, they quickly oxidize or react.

The second group of metals - alkaline earth metals - are much closer to the main groups. The name "alkaline earth" comes from ancient times, when oxides were called "earths" because they had a loose, crumbly structure. Metals starting from group 3 have more or less familiar (in the everyday sense) properties. As the group number increases, the amount of metals decreases, being replaced by non-metallic elements. The last group consists of inert (or noble) gases.

Determination of metals and non-metals in the periodic table. Simple and complex substances.

Simple substances (metals and non-metals)

Conclusion

The ratio of metals and non-metals in the periodic table clearly weighs in favor of the former. This situation indicates that the group of metals is combined too broadly and requires a more detailed classification, which is recognized by the scientific community.

Moscow State Geological Exploration

University named after S. Ordzhonikidze

Department of Chemistry

Abstract and laboratory work

On topic: "Metals"

Moscow, 2003

PROPERTIES COMMON TO ALL METALS

The main chemical property of metals is the ability of their atoms to easily give up their electrons and become a positively charged ion. Typical metals never gain electrons; their ions are positively charged.

By easily giving up their valence electrons during chemical reactions, metals are reducing agents. The easier a metal gives up its electrons, the more active it is, the more energetically it interacts with other substances. Due to their different affinities for oxygen, metals are capable of reducing other metals from their oxides at high temperatures.

From the outside (physical properties), metals are characterized primarily by a special “metallic luster”, which is determined by their ability to strongly reflect rays of light. Also, typical metals have high thermal and electrical conductivity. Moreover, metals arranged in the same order can conduct heat anyway: the best conductors are silver and copper, the worst are lead and mercury. As the temperature increases, the conductivity of metals decreases; when it decreases, on the contrary, it increases.

A very important property of metals is their relatively easy mechanical deformability. Metals are ductile, they are easily forged, drawn into wire, etc.

Metal crystals consist of positively charged ions and free electrons split off from the corresponding atoms. the entire crystal can be imagined in the form of a spatial lattice, the nodes of which are occupied by ions, and in the gaps there are easily mobile electrons. These electrons constantly move from one atom to another and rotate around the nucleus of one or another atom. Thus, the high electrical conductivity of metals is explained by the presence of free electrons in them. The presence of free electrons also determines the high thermal conductivity of metals. Being in continuous motion, electrons constantly collide with ions and exchange energy with them.

The plasticity of metals is also directly related to their internal structure, which allows for easy sliding of some layers of ions relative to others under the influence of external influences. When the homogeneity of the structure is disrupted by the addition of another metal, the alloys are hard and brittle. Based on their density, metals are conventionally divided into two groups: light metals (density< 5 г/см 3) и тяжелые металлы – все остальные.

All metals, except mercury, are solids at ordinary temperatures. Light metals are more fusible, heavy metals are refractory. The boiling points of metals are very high.

POSITION OF METALS IN THE PERIODLEEV TABLE. IONIZATION POTENTIALS.

In the periodic table of D.I. Mendeleev, metals occupy the entire lower left part, and the boundary goes beyond the diagonal line drawn from the upper left corner. In accordance with the characteristics of the electronic structure and position in the periodic table, s-, p-, d- and f- metals are distinguished. S-metals include elements in which the outer s-level is filled. These are elements of the main subgroups of PS groups I and II - alkali and alkaline earth metals. The p-metals include elements of groups III – IV. These metals are typical semiconductors. A characteristic feature of these elements is the formation of amphoteric hydroxides. d-metals are called transition metals. Each family consists of 10 d-elements. The maximum possible oxidation state of d-metals is +8. The most characteristic feature of d-elements is their exceptional ability to form complexes. In this they differ sharply from intransitive elements. The chemistry with the complementary f-layers is formed by two groups of elements - lanthanides and actinides. Lanthanides are rare earth elements. Their typical oxidation state is +3. Among actinides, the majority are radioactive elements. They are capable of exhibiting several states of oxidation. Metals of the IV and VII periods are also called heavy metals, due to their high density, in contrast to the light metals of the first three periods.

Ionization potential

By group By period

Metal metal

METALS IN NATURE AND THEIR CLARKS

s-metals occur in nature only in the form of compounds, either in minerals (KCl, NaCl, CaCO 3, etc.) or as ions in sea water. Aluminum is the most common metal on Earth (8% of the composition of the earth's crust). It does not occur in nature as a free metal; is part of alumina (Al 2 O 3), bauxite (Al 2 O 3  xH 2 O).

Gold and platinum are found almost exclusively in native form, and silver and copper - partly; Sometimes native mercury is found.

Minerals and rocks containing metal compounds and suitable for producing these metals are called ores.

Dissipated state - when elements do not form or almost do not form their own minerals.

Forms of occurrence of metals:

Minerals:

A) oxides

B) halides

B) sulfides

D) selenides

D) carbonates

E) silicates

Rare trace elements: Te, Ge, Cd.

Native elements: Cu, Au, Ag, Pt.

The Clarke values ​​of most elements do not exceed 0.01–0.0001%; ​​such elements are called rare.

SERIES OF STRESSES OF METALS

The stress series is the Beketov displacement series. He arranged the metals according to their decreasing chemical reactivity.

If, from the entire series of standard electrode potentials, we select only those electrode processes that correspond to the general equation:

then we get a series of metal stresses. Hydrogen is always placed in this row, which makes it possible to see which metals are capable of displacing hydrogen from aqueous solutions of acids. The position of a particular metal in the stress series characterizes its ability to undergo redox interactions in aqueous solutions under standard conditions.

Reduction of chemical activity

K, Ca, Na, Mg, Al, Mn, Zn, Fe, Ni, Sn, Pb, H2, Cu, Hg, Ag, Au

Reducing the ability of ions to gain electrons

Me n+ + ne Me 0

In this series, the position of each metal is precisely determined by the magnitude of the electrical voltage, or potential difference. Hydrogen is also placed in this row because it can also displace some metals from solutions of their salts.

Chemical behavior of individual metals during reactions in solutions:

Each metal in this series (and hydrogen) displaces (reduces) all the metals following it from solutions of their salts. In turn, it itself can be displaced (restored) by any of the metals in front of it.

Metals in the voltage series up to hydrogen can displace it from dilute acids. Metals to the right of hydrogen are not able to displace hydrogen from acids.

The further to the left in the series the voltage of Me is, the more active it is, the greater its reducing ability in relation to ions of other metals, the easier it itself turns into ions.

Electronic Process Equation		Electrode Process Equation	Standard potential φ 0 at 25 0 C.
Li + + ē - = Li Rb + + ē - = Rb K + + ē - = K Cs + + ē - = Cs Ca 2+ + 2ē - = Ca Na + + ē - = Na Mg 2+ + 2ē - = Mg Al 3+ + 3ē - = Al Ti 2+ + 2ē - = Ti Mn 2+ + 2ē - = Mn Cr 2+ + 2ē - = Cr Zn 2+ + 2ē - = Zn Cr 3+ + 3ē - = Cr Fe 2+ + 2ē - = Fe Cd 2+ + 2ē - = Cd		Co 2+ + 2ē - = Co Ni 2+ +2ē - = Ni Sn 2+ + 2ē - = Sn Pb 2+ + 2ē - = Pb Fe 3+ + 3ē - = Fe 2H + + 2ē - = H 2 Bi 3+ + 3ē - = Bi Cu 2+ + 2ē - = Cu Cu + + ē - = Cu Hg 2 2+ + 2ē - = 2Hg Ag + + ē - = Ag Hg 2+ + 2ē - = Hg Pt 2+ + 2ē - = Pt Au 3+ + 3ē - = Au Au + + ē - = Au

CHEMICAL BONDING IN METALS.

Mobile free electrons determine the electrical conductivity of metals, the photoelectric effect, and electrochemical properties.

Following the method of molecular orbitals, we need to imagine the general on which all the valence electrons are located. When two hydrogen atoms come together, each energy level splits into M sublevels. An increase in the number of levels caused by the approach of atoms leads to the formation of bands corresponding to s-electrons, p-electrons, etc.

A characteristic difference between transition metals and typical metals is that the former have a noticeable overlap of energy bands (s, p, d). Atoms in metals are bonded more tightly than in individual molecules made up of the same atoms. The lengths of bonds in metals are longer than the lengths of bonds in molecules, therefore, each bond is weaker than a molecular one, but their total number is large. The valence electrons of all atoms in a metal give rise to forces that bind the metal atoms to each other. Consequently, “free electrons” are electrons that have the ability to move throughout the entire mass of the metal, but they are not “free” from the action of forces and are in the periodic field of metal ions that form its crystal lattice.

INTERACTION OF METALS WITH WATER

Oxides, peroxides and superoxides of s-elements react with water, forming an alkali:

Na 2 + H 2 O = 2NaOH

BaO 2 +2H 2 O = Ba(OH) 2 +H 2 O 2

2KO 2 +2H 2 O = 2KOH + H 2 O 2 + O 2

The surface of aluminum is usually covered with a durable film of Al 2 O 3 oxide, which protects aluminum from interaction with the environment. If this film is removed, the metal can react vigorously with water:

2Al + 6H 2 O +2Al(OH) 3 +3H 2

2Cr + 3H 2 O = Cr 2 O 3 + 3H 2

Еh – pH WATER DIAGRAM:

2H2O - 4e O2 + 4H +

О2 + 4Н + +4е 2Н2О

H + + e 1/2H2

– interact with H2O and displace H

– do not interact with H2O

Interact with H2O and do not displace H

Look around for a second... How many metal things can you see? Typically, when we think of metals, we think of substances that are shiny and durable. However, they are also found in our food and in our bodies. Let's get acquainted with the complete list of metals known to science, learn their basic properties and find out why they are so special.

Elements that easily lose electrons, 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 are also important for the production of almost all objects. There is metal even in the human body. When you look at a multivitamin's nutritional label, you'll see dozens of compounds listed.

What you may not know is that elements such as sodium, calcium, magnesium and zinc are essential for life and if they are missing from our bodies, our health can be in serious danger. For example, calcium is necessary for healthy bones, magnesium for metabolism. Zinc boosts immune system function, and iron helps blood cells carry oxygen throughout the body. However, the metals in our bodies are different from the metal in a spoon or steel bridge in that they have lost electrons. They are called cations.

Metals also have antibiotic properties, which is why railings and handles in public places are often made from these elements. It is known that many instruments are made of silver to prevent the growth of bacteria. Artificial joints are made from titanium alloys, which both prevent infection and make recipients stronger.

Metals in the periodic table

All elements in Dmitry Mendeleev are divided into two large groups: metals and non-metals. The first is the most numerous. Most elements are metals (blue). Nonmetals in the table are shown on a yellow background. There is also a group of elements that are classified as metalloids (red). All metals are grouped on the left side of the table. Notice that hydrogen is grouped with metals in the upper left corner. Despite this, it is considered non-metallic. However, some scientists theorize that there may be metallic hydrogen in the core of the planet Jupiter.

Metal bondage

Many of the wonderful and beneficial qualities of an element come from the way its atoms bond together. In this case, certain connections arise. The metallic interaction of atoms results in the creation of metallic structures. Every instance of this element in everyday life, from a car to coins in a pocket, involves a metal connection.

During this process, the metal atoms share their outer electrons evenly with each other. Electrons flowing between positively charged ions easily transfer heat and electricity, making these elements such good conductors of heat and electricity. Copper wires are used for power supply.

Metal reactions

Reactivity refers to the tendency of an element to react with chemicals in its environment. It can be different. Some metals, such as potassium and sodium (in columns 1 and 2 of the periodic table), react easily with many different chemicals and are rarely found in their pure, elemental form. Both usually exist only in compounds (bonded to one or more other elements) or as ions (a charged version of their elemental form).

On the other hand, there are other metals, they are also called jewelry. Gold, silver and platinum are not very reactive and are usually found in pure form. lose electrons more easily than nonmetals, but not as easily as reactive metals such as sodium. Platinum is relatively unreactive and very resistant to reactions with oxygen.

Element properties

When you learned the alphabet in elementary school, you discovered that all letters have their own unique set of properties. For example, some had straight lines, some had curves, and others had both types of lines. The same can be said about the elements. Each of them has a unique set of physical and chemical properties. Physical properties are qualities inherent in certain substances. Shiny or not, how well it conducts heat and electricity, at what temperature it melts, how high its density is.

Chemical properties include those qualities that are observed when exposed to oxygen if they were to burn (how difficult it would be for them to retain their electrons during a chemical reaction). Different elements may have common properties. For example, iron and copper are both elements that conduct electricity. However, they do not have the same properties. For example, when iron is exposed to humid air, it becomes rusty, but when copper is exposed to the same conditions, it acquires a specific green patina. That's why the Statue of Liberty is green and not rusty. It is made of copper, not iron).

Organization of elements: metals and nonmetals

The fact that elements have some common and unique properties allows them to be sorted into a nice, neat diagram called the periodic table. It organizes elements based on their atomic number and properties. So, in the periodic table we find elements grouped together that have common properties. Iron and copper are close to each other, both are metals. Iron is represented by the symbol "Fe" and copper is represented by the symbol "Cu".

Most of the elements in the periodic table - and they tend to be on the left side of the table. They are grouped together because they have certain physical and chemical properties. For example, metals are dense, shiny, good conductors of heat and electricity, and they easily lose electrons in chemical reactions. In contrast, nonmetals have the opposite properties. They are not dense, do not conduct heat or electricity, and tend to gain electrons rather than give them away. When we look at the periodic table, we see that most nonmetals are grouped on the right. These are elements such as helium, carbon, nitrogen and oxygen.

What are heavy metals?

The list of metals is quite numerous. Some of them can accumulate in the body without causing harm to it, such as natural strontium (formula Sr), which is an analogue of calcium, since it is productively deposited in bone tissue. Which ones are called heavy and why? Let's look at four examples: lead, copper, mercury and arsenic.

Where are these elements located and how do they affect the environment and human health? Heavy metals are metallic, naturally occurring compounds that have very high densities compared to other metals—at least five times the density of water. They are toxic to humans. Even small doses can lead to serious consequences.

• Lead. It is a heavy metal that is toxic to people, especially children. Poisoning with this substance can lead to neurological problems. Although it was once very attractive due to its flexibility, high density and ability to absorb harmful radiation, lead has been phased out in many ways. This soft, silvery metal, which is found on Earth, is dangerous to humans and accumulates in the body over time. The worst thing is that you cannot get rid of it. It sits there, accumulates and gradually poisons the body. Lead is toxic to the nervous system and can cause severe brain damage in children. It was widely used in the 1800s to create makeup and was used as an ingredient in hair dye until 1978. Today, lead is used primarily in large batteries, as shields for X-rays, or as insulation for radioactive material.
• Copper. It is a reddish-brown heavy metal that has many uses. Copper is still one of the best conductors of electricity and heat, and many electrical wires are made from this metal and covered with plastic. Coins, mostly small change, are also made from this element of the periodic table. Acute copper poisoning is rare, but like lead, it can accumulate in tissues, eventually leading to toxicity. People who are exposed to large amounts of copper or copper dust are also at risk.
• Mercury. This metal is toxic in any form and can even be absorbed by the skin. Its uniqueness lies in the fact that it is liquid at room temperature and is sometimes called "fast silver". It can be seen in a thermometer because as a liquid it absorbs heat, changing volume with even the slightest difference in temperature. This allows the mercury to rise or fall in the glass tube. Because this substance is a potent neurotoxin, many companies are switching to red-colored ones.
• Arsenic. From Roman times until the Victorian era, arsenic was considered the “king of poisons” as well as the “poison of kings.” History is riddled with countless examples of both royalty and common people committing murder for personal gain using arsenic compounds that had no smell, color or taste. Despite all the negative effects, this metalloid also has its own areas of application, even in medicine. For example, arsenic trioxide is a very effective drug used to treat people with acute promyelocytic leukemia.

What is a precious metal?

A precious metal is a metal that can be rare or difficult to obtain and is also economically very valuable. What is the list of metals that are precious? There are three in total:

• Platinum. Despite its refractory nature, it is used in jewelry, electronics, automobiles, chemical processes, and even medicine.
• Gold. This precious metal is used to make jewelry and gold coins. However, it has many other uses. It is used in medicine, manufacturing and laboratory equipment.
• Silver. This noble silvery-white metal is highly malleable. in its pure form it is quite heavy, it is lighter than lead, but heavier than copper.

Metals: types and properties

Most elements can be considered metals. They are grouped in the middle on the left side of the table. Metals are alkali, alkaline earth, transition, lanthanide and actinide.

They all have several common properties, these are:

• solid at room temperature (except mercury);
• usually shiny;
• with a high melting point;
• good conductor of heat and electricity;
• with low ionization ability;
• with low electronegativity;
• malleable (able to take a given shape);
• plastic (can be pulled into wire);
• with high density;
• a substance that loses electrons in reactions.

List of metals known to science

1. lithium;
2. beryllium;
3. sodium;
4. magnesium;
5. aluminum;
6. potassium;
7. calcium;
8. scandium;
9. titanium;
10. vanadium;
11. chromium;
12. manganese;
13. iron;
14. cobalt;
15. nickel;
16. copper;
17. zinc;
18. gallium;
19. rubidium;
20. strontium;
21. yttrium;
22. zirconium;
23. niobium;
24. molybdenum;
25. technetium;
26. ruthenium;
27. rhodium;
28. palladium;
29. silver;
30. cadmium;
31. indium;
32. copernicium;
33. cesium;
34. barium;
35. tin;
36. iron;
37. bismuth;
38. lead;
39. mercury;
40. tungsten;
41. gold;
42. platinum;
43. osmium;
44. hafnium;
45. germanium;
46. iridium;
47. niobium;
48. rhenium;
49. antimony;
50. thallium;
51. tantalum;
52. francs;
53. livermorium.

In total, about 105 chemical elements are known, most of which are metals. The latter are a very common element in nature, which is found both in pure form and as part of various compounds.

Metals lie in the depths of the earth; they can be found in various bodies of water, in the bodies of animals and humans, in plants and even in the atmosphere. In the periodic table they are arranged starting with lithium (a metal with the formula Li) and ending with livermorium (Lv). The table continues to be replenished with new elements, and these are mainly metals.

DEFINITION

Metals- a group of elements, in the form of simple substances, with characteristic metallic properties, such as high thermal and electrical conductivity, positive temperature coefficient of resistance, high ductility, malleability and metallic luster.

Finding metals in nature

Metals are widespread in nature and can be found in various forms: in the native state (Ag, Au, Rt, Cu), in the form of oxides (Fe 3 O 4, Fe 2 O 3, (NaK) 2 O × AlO 3), salts (KCl, BaSO 4, Ca 3 (PO 4) 2), and also accompany various minerals (Cd - zinc ores, Nb, Tl - tin, etc.).

By abundance in the earth's crust (in mass percentage), metals are distributed as follows: Al, Fe, Ca, Na, Mg, K, Ti - 8.2%, 4.1%, 4.1%, 2.3% 2. 3%, 2.1%, and 0.56%, respectively. Sodium and magnesium are contained in sea water - 0.12 and 1.05%, respectively.

Physical properties of metals

All metals have a metallic luster (however, In and Ag reflect light better than other metals), hardness (the hardest metal is Cr, the softest metals are alkali metals), ductility (in the series Au, Ag, Cu, Sn, Pb, Zn, Fe there is decrease in ductility), malleability, density (the lightest metal is Li, the heaviest is Os), heat and electrical conductivity, which decrease in the order of Ag, Cu, Au, Al, W, Fe.

Depending on the boiling point, all metals are divided into refractory (T kip > 1000C) and low-melting (T kip< 1000С). Примером тугоплавких металлов может быть – Au, Cu, Ni, W, легкоплавких – Hg, K, Al, Zn.

Electronic structure of metals

Among the metals there are s-, p-, d- and f-elements. Thus, s-elements are metals of groups I and II of the Periodic Table (ns 1, ns 2), p-elements are metals located in groups III – VI (ns 2 np 1-4). D-element metals have a larger number of valence electrons compared to s- and p-element metals. The general electronic configuration of the valence electrons of d-element metals is (n-1)d 1-10 ns 2 . Starting from the 6th period, metals f-elements appear, which are combined into families of 14 elements (due to similar chemical properties) and bear the special names of lanthanides and actinides. The general electronic configuration of the valence electrons of f-element metals is (n-2)f 1-14 (n-1)d 0-1 ns 2 .

Obtaining metals

Alkali, alkaline earth metals and aluminum are obtained by electrolysis of molten salts or oxides of these elements:

2NaCl = 2Na + Cl2

CaCl 2 = Ca + Cl 2

2Al 2 O 3 = 4Al + 3O 2

Heavy metals are obtained by reduction from ores at high temperatures and in the presence of a catalyst (pyrometallurgy) (1) or reduction from salts in solution (hydrometallurgy) (2):

Cu 2 O + C = 2Cu + CO (1)

CuSO 4 + Fe = Cu + FeSO 4 (2)

Some metals are obtained by thermal decomposition of their unstable compounds:

Ni(CO) 4 = Ni + 4CO

Chemical properties of metals

Metals are capable of reacting with simple substances such as oxygen (combustion reaction), halogens, nitrogen, sulfur, hydrogen, phosphorus and carbon:

2Al + 3/2 O 2 = Al 2 O 3 (aluminum oxide)

2Na + Cl 2 = 2NaCl (sodium chloride)

6Li + N 2 = 2Li 3 N (lithium azide)

2Li+2C = Li 2 C 2 (lithium carbide)

2K +S = K 2 S (potassium sulfide)

2Na + H2 = NaH (sodium hydride)

3Ca + 2P = Ca 3 P 2 (calcium phosphide)

Metals interact with each other, forming intermetallic compounds:

3Cu + Au = Cu 3 Au

Alkali and some alkaline earth metals (Ca, Sr, Ba) react with water to form hydroxides:

Ba + 2H 2 O = Ba(OH) 2 + H 2

2Na + 2H 2 O = 2NaOH + H 2

In ORR, metals are reducing agents - they give up valence electrons and turn into cations. The reducing ability of a metal is its position in the electrochemical voltage series of metals. Thus, the further to the left a metal is in the series of stresses, the stronger the reducing properties it exhibits.

Metals in the activity series up to hydrogen are able to react with acids:

2Al + 6HCl = 2AlCl3 + 3H2

Zn + 2HCl = ZnCl 2 + 2H 2

Fe + H 2 SO 4 = FeSO 4 + H 2

Examples of problem solving

EXAMPLE 1

EXAMPLE 2

Exercise	When a mixture of copper and iron weighing 20 g was exposed to excess hydrochloric acid, 5.6 liters of gas (n.s.) were released. Determine the mass fractions of metals in the mixture.
Solution	Copper does not react with hydrochloric acid, since it is in the activity series of metals after hydrogen, i.e. The release of hydrogen occurs only as a result of the interaction of acid with iron. Let's write the reaction equation: Fe + 2HCl = FeCl 2 + H 2 Let's find the amount of hydrogen substance: v(H 2) = V(H 2) / V m = 5.6 / 22.4 = 0.25 mol According to the reaction equation: v(H 2) = v(Fe) = 0.25 mol Let's find the mass of iron: m(Fe)= v(Fe) M(Fe) = 0.25 56 = 14 g. Let's calculate the mass fractions of metals in the mixture: ω Fe = m Fe /m mixture = 14 / 20 = 0.7 = 70% ω Cu = 100 – 70 = 30%
Answer	Mass fractions of metals in the mixture: 70% iron, 30% copper

Metals chemistry message will briefly tell you a lot of useful information about these chemical elements. Also, a message about metals will help you prepare for class.

Report on chemistry “Metals”

Today, metals are widespread in nature and are found in the waters of rivers, seas, oceans, lakes, in the bowels of the earth, even in the bodies of plants, animals and the atmosphere.

Properties of metals:

• Crystalline dense structure
• Metallic shine
• Electrical conductivity
• High thermal conductivity
• Electrical conductivity decreases with increasing temperature
• Easily donates electrons
• Flexibility and malleability
• Can form alloys

Metals and alloys are divided into 2 groups:

1. Ferrous metals and its alloys

Alloys include steel and cast iron. Nickel, chromium, tungsten, cobalt, titanium, molybdenum, vanadium and other metals are used in technology. They are obtained by alloying. They have high strength, abrasion resistance, and corrosion resistance.

2. Non-ferrous metals and its alloys

They are so called because their coloring is varied. Copper, for example, copper is light red, tin, silver, nickel are white, gold is yellow, and lead is bluish-white. Alloys of non-ferrous metals are widely used in jewelry.

Often, noble metals - gold, silver, ruthenium and platinum - are also separated from non-ferrous and ferrous metals. They do not oxidize in air and are not destroyed even when exposed to alkalis and acids.

Chemical properties of metals

The main chemical property is the ability of atoms to easily give up valence electrons and become positively charged ions. Typical metals do not add electrons - their ions are always positive. Therefore, they are considered energetic reducers. And the more easily a certain metal gives up electrons, the more active it becomes and reacts more energetically with other metals. This chemical property was studied by the Russian scientist Beketov, who arranged them in descending order of chemical activity, the so-called “displacement row”. Metals arranged in ascending order form an electrochemical series of voltages. It looks like this: Li, Rb, K, Ba, Sr, Ca, Na, Mg, Al, Mn, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, H, Sb, Bi, Cu, Hg , Ag, Pd, Pt, Au.

Chemical properties of metals:

• The lower the electrode potential of a metal, the higher its reducing ability.
• A metal can displace metals from salt solutions that come after it in the stress series.
• Metals with a negative standard electrode potential can displace from acid solutions metals that are to the left of hydrogen in the voltage series.
• Metals have electromechanical and chemical activity.

Where are metals used?

Metals are used in the following areas:

• In the construction industry

Metals are the main structural materials due to their homogeneity, high strength and impermeability to gases and liquids. Thanks to the ability to change the recipe of alloys, it is possible to change their properties.

• In the electrical industry

Metals are excellent conductors of electricity, especially aluminum and copper. They are used for electric heating elements and resistors as a material with increased resistance.

• For the production of tool materials

Alloys and metals are used to make the working part of tools. These are mainly steel, hard alloys, diamond, ceramics and boron nitride.

We hope that the report on the topic “Metals” helped you learn new information about these chemical elements. You can add a message on chemistry on the topic “Metals” using the comment form below.