What are the general physical properties of metals?

General characteristics of metals

   If in D.I. Mendeleev’s periodic table of elements we draw a diagonal from beryllium to astatine, then on the lower left along the diagonal there will be metal elements (these also include elements of side subgroups, highlighted in blue), and on the upper right - non-metal elements (highlighted yellow). Elements located near the diagonal - semimetals or metalloids (B, Si, Ge, Sb, etc.) have a dual character (highlighted in pink).

 As can be seen from the figure, the vast majority of elements are metals.

By their chemical nature, metals are chemical elements whose atoms give up electrons from external or pre-external energy levels, forming positively charged ions.

Almost all metals have relatively large radii and a small number of electrons (from 1 to 3) at the outer energy level. Metals are characterized by low electronegativity values ​​and reducing properties.

The most typical metals are located at the beginning of the periods (starting from the second), then from left to right the metallic properties weaken. In the group from top to bottom, the metallic properties increase as the radius of the atoms increases (due to an increase in the number of energy levels). This leads to a decrease in electronegativity (the ability to attract electrons) of elements and an increase in reducing properties (the ability to donate electrons to other atoms in chemical reactions).

Typical metals are s-elements (IA-group elements from Li to Fr. PA-group elements from Mg to Ra). The general electronic formula of their atoms is ns1-2. They are characterized by oxidation states + I and + II, respectively.

The small number of electrons (1-2) in the outer energy level of typical metal atoms means that these electrons are easily lost and exhibit strong reducing properties, as reflected by low electronegativity values. This implies the limited chemical properties and methods of obtaining typical metals.

A characteristic feature of typical metals is the tendency of their atoms to form cations and ionic chemical bonds with non-metal atoms. Compounds of typical metals with nonmetals are ionic crystals of “metalanion of a nonmetal,” for example, K+ Br—, Ca2+ O2-. Cations of typical metals are also included in compounds with complex anions - hydroxides and salts, for example Mg2+(OH-)2, (Li+)2CO32-.

The A-group metals that form the amphoteric diagonal in the Periodic Table Be-Al-Ge-Sb-Po, as well as the metals adjacent to them (Ga, In, Tl, Sn, Pb, Bi) do not exhibit typical metallic properties.

The general electronic formula of their atoms ns 2 np 0-4 suggests a greater variety of oxidation states, a greater ability to retain their own electrons, a gradual decrease in their reducing ability and the appearance of oxidizing ability, especially in high oxidation states (typical examples are compounds Tl III, PbIV, Biv) .

Similar chemical behavior is characteristic of most (d-elements, i.e. elements of the B-groups of the Periodic Table (typical examples are the amphoteric elements Cr and Zn).

This manifestation of duality (amphoteric) properties, both metallic (basic) and non-metallic, is due to the nature of the chemical bond. In the solid state, compounds of atypical metals with nonmetals contain predominantly covalent bonds (but less strong than bonds between nonmetals).

In solution, these bonds are easily broken, and the compounds dissociate into ions (in whole or in part).

For example, the metal gallium consists of Ga2 molecules; in the solid state, the chlorides of aluminum and mercury (II) AlCl3 and HgCl2 contain strongly covalent bonds, but in solution AlCl3 dissociates almost completely, and HgCl2 - to a very small extent (and even then into HgCl+ and Cl—).

General physical properties of metals

Due to the presence of free electrons ("electron gas") in the crystal lattice, all metals exhibit the following characteristic general properties:

1) Plasticity - the ability to easily change shape, stretch into wire, roll into thin sheets.

2) Metallic luster and opacity. This is due to the interaction of free electrons with light incident on the metal.

3) Electrical conductivity. It is explained by the directional movement of free electrons from the negative pole to the positive one under the influence of a small potential difference. When heated, electrical conductivity decreases, because As the temperature increases, vibrations of atoms and ions in the nodes of the crystal lattice intensify, which complicates the directional movement of the “electron gas”.

4) Thermal conductivity. It is caused by the high mobility of free electrons, due to which the temperature quickly equalizes over the mass of the metal. The highest thermal conductivity is found in bismuth and mercury.

5) Hardness. The hardest is chrome (cuts glass); the softest alkali metals - potassium, sodium, rubidium and cesium - are cut with a knife.

6) Density. The smaller the atomic mass of the metal and the larger the radius of the atom, the smaller it is. The lightest is lithium (ρ=0.53 g/cm3); the heaviest is osmium (ρ=22.6 g/cm3). Metals with a density of less than 5 g/cm3 are considered “light metals”.

7) Melting and boiling points. The most fusible metal is mercury (mp = -39°C), the most refractory metal is tungsten (mp = 3390°C). Metals with melting temperature above 1000°C are considered refractory, below – low-melting.

General chemical properties of metals

Strong reducing agents: Me0 – nē → Men+

A number of voltages characterize the comparative activity of metals in redox reactions in aqueous solutions.

I. Reactions of metals with non-metals

1) With oxygen:
2Mg + O2 → 2MgO

2) With sulfur:
Hg + S → HgS

3) With halogens:
Ni + Cl2 –t°→ NiCl2

4) With nitrogen:
3Ca + N2 –t°→ Ca3N2

5) With phosphorus:
3Ca + 2P –t°→ Ca3P2

6) With hydrogen (only alkali and alkaline earth metals react):
2Li + H2 → 2LiH

Ca + H2 → CaH2

II. Reactions of metals with acids

1) Metals in the electrochemical voltage series up to H reduce non-oxidizing acids to hydrogen:

Mg + 2HCl → MgCl2 + H2

2Al+ 6HCl → 2AlCl3 + 3H2

6Na + 2H3PO4 → 2Na3PO4 + 3H2

2) With oxidizing acids:

When nitric acid of any concentration interacts with concentrated sulfuric acid with metals, hydrogen is never released!

Zn + 2H2SO4(K) → ZnSO4 + SO2 + 2H2O

4Zn + 5H2SO4(K) → 4ZnSO4 + H2S + 4H2O

3Zn + 4H2SO4(K) → 3ZnSO4 + S + 4H2O

2H2SO4(k) + Cu → Cu SO4 + SO2 + 2H2O

10HNO3 + 4Mg → 4Mg(NO3)2 + NH4NO3 + 3H2O

4HNO3(k) + Cu → Cu (NO3)2 + 2NO2 + 2H2O

III. Interaction of metals with water

1) Active (alkali and alkaline earth metals) form a soluble base (alkali) and hydrogen:

2Na + 2H2O → 2NaOH + H2

Ca+ 2H2O → Ca(OH)2 + H2

2) Metals of medium activity are oxidized by water when heated to an oxide:

Zn + H2O –t°→ ZnO + H2

3) Inactive (Au, Ag, Pt) - do not react.

IV. Displacement of less active metals by more active metals from solutions of their salts:

Cu + HgCl2 → Hg+ CuCl2

Fe+ CuSO4 → Cu+ FeSO4

In industry, they often use not pure metals, but their mixtures - alloys , in which the beneficial properties of one metal are complemented by the beneficial properties of another. Thus, copper has low hardness and is unsuitable for the manufacture of machine parts, while alloys of copper and zinc ( brass ) are already quite hard and are widely used in mechanical engineering.

Aluminum has high ductility and sufficient lightness (low density), but is too soft. Based on it, an alloy with magnesium, copper and manganese is prepared - duralumin (duralumin), which, without losing the beneficial properties of aluminum, acquires high hardness and becomes suitable for aircraft construction.

Alloys of iron with carbon (and additions of other metals) are the well-known cast iron and steel.

Metals in their free form are reducing agents. However, the reactivity of some metals is low due to the fact that they are covered with a surface oxide film , which is resistant to varying degrees to the action of chemical reagents such as water, solutions of acids and alkalis.

For example, lead is always covered with an oxide film; its transition into solution requires not only exposure to a reagent (for example, dilute nitric acid), but also heating. The oxide film on aluminum prevents its reaction with water, but is destroyed by acids and alkalis. A loose oxide film (rust ) that forms on the surface of iron in humid air does not interfere with further oxidation of iron.

Under the influence of concentrated stable is formed on metals . This phenomenon is called passivation . Thus, in concentrated sulfuric acid, metals such as Be, Bi, Co, Fe, Mg and Nb are passivated (and then do not react with the acid), and in concentrated nitric acid - metals A1, Be, Bi, Co, Cr, Fe , Nb, Ni, Pb, Th and U.

When interacting with oxidizing agents in acidic solutions, most metals transform into cations, the charge of which is determined by the stable oxidation state of a given element in compounds (Na+, Ca2+, A13+, Fe2+ and Fe3+)

The reducing activity of metals in an acidic solution is transmitted by a series of stresses. Most metals are transferred into solution with hydrochloric and dilute sulfuric acids, but Cu, Ag and Hg - only with sulfuric (concentrated) and nitric acids, and Pt and Au - with “regia vodka”.

Metal corrosion

An undesirable chemical property of metals is their corrosion, i.e. active destruction (oxidation) upon contact with water and under the influence of oxygen dissolved in it (oxygen corrosion). For example, the corrosion of iron products in water is widely known, as a result of which rust forms and the products crumble into powder.

Corrosion of metals also occurs in water due to the presence of dissolved gases CO2 and SO2; an acidic environment is created, and H+ cations are displaced by active metals in the form of hydrogen H2 ( hydrogen corrosion ).

contact corrosion) can be especially corrosive A galvanic couple occurs between one metal, for example Fe, and another metal, for example Sn or Cu, placed in water. The flow of electrons goes from the more active metal, which is to the left in the voltage series (Re), to the less active metal (Sn, Cu), and the more active metal is destroyed (corroded).

It is because of this that the tinned surface of cans (iron coated with tin) rusts when stored in a humid atmosphere and handled carelessly (iron quickly collapses after even a small scratch appears, allowing the iron to come into contact with moisture). On the contrary, the galvanized surface of an iron bucket does not rust for a long time, since even if there are scratches, it is not the iron that corrodes, but the zinc (a more active metal than iron).

Corrosion resistance for a given metal increases when it is coated with a more active metal or when they are fused ; Thus, coating iron with chromium or making an alloy of iron and chromium eliminates corrosion of iron. Chromed iron and steel containing chromium ( stainless steel ) are highly resistant to corrosion.

  General methods of obtaining metals in industry:

• electrometallurgy , i.e., the production of metals by electrolysis of melts (for the most active metals) or salt solutions;

• pyrometallurgy , i.e. the recovery of metals from ores at high temperatures (for example, the production of iron in the blast furnace process);

• hydrometallurgy , i.e., the separation of metals from solutions of their salts by more active metals (for example, the production of copper from a CuSO4 solution by the action of zinc, iron or aluminum).

Native metals are sometimes found in nature (typical examples are Ag, Au, Pt, Hg), but more often metals are found in the form of compounds ( metal ores ). Metals vary in abundance in the earth's crust: from the most common - Al, Na, Ca, Fe, Mg, K, Ti) to the rarest - Bi, In, Ag, Au, Pt, Re.

Source: http://himege.ru/obshhaya-xarakteristika-metallov/

Physical and chemical properties of metals – Osvarke.Net

The article discusses in detail the physical and chemical properties of metals.

Physical properties

The physical properties of metals include color, density, melting point, thermal conductivity, thermal expansion, heat capacity, electrical conductivity, magnetic properties, etc.

Color refers to the ability of metals to reflect light of a certain wavelength. For example, copper is pink-red in color, aluminum is silver-white.

The density of a metal is characterized by its mass contained in a unit volume. Based on density, all metals are divided into light (less than 4500 kg/m3) and heavy. Density is of great importance when creating various products. For example, in aircraft and rocket production they strive to use lighter metals and alloys (aluminum, magnesium, titanium), which helps reduce the weight of products.

Melting temperature

Melting point is the temperature at which a metal changes from solid to liquid. Refractory metals are distinguished by melting temperature (tungsten 3416°C, tantalum 2950°C, titanium 1725°C, etc.

) and low-melting (tin 232°C, lead 327°C, zinc 419.5°C, aluminum 660°C). Melting point is of great importance when choosing metals for the manufacture of cast products, welded and soldered joints, thermoelectric devices and other products.

In SI units, the melting point is expressed in degrees Kelvin (K).

Thermal conductivity

Thermal conductivity is the ability of metals to transfer heat from hotter to cooler areas of the body. Silver, copper, and aluminum have high thermal conductivity. Iron has a thermal conductivity about three times less than aluminum and five times less than copper.

Thermal conductivity is of great importance when choosing materials for parts. For example, if a metal conducts heat poorly, then when heated and rapidly cooled (heat treatment, welding), cracks form in it. Some machine parts (engine pistons, turbine blades) must be made of materials with good thermal conductivity.

In SI units, thermal conductivity has the dimension W/(m∙K).

Thermal expansion

Thermal expansion is the ability of metals to expand in size when heated and shrink when cooled. Thermal expansion is characterized by the coefficient of linear expansion α=(l2-l1)/[l1(t2-t1)], where l1 and l2 are the lengths of the body at temperatures t1 and t2.

The coefficient of volumetric expansion is 3α.

Thermal expansion must be taken into account when welding, forging and hot stamping, manufacturing casting molds, dies, rolling rolls, gauges, making precision connections and assembling instruments, during the construction of bridge trusses, and laying railway rails.

Heat capacity

Heat capacity is the ability of a metal to absorb a certain amount of heat when heated. In SI units it has the dimension J/K. The heat capacity of various metals is compared by the specific heat capacity - the amount of heat, expressed in large calories, that is required to increase the temperature of 1 kg of metal by 1 ° C (in SI units - J / (kg∙K).

Ability to conduct electric current

The ability of metals to conduct electric current is assessed by two mutually opposite characteristics - electrical conductivity and electrical resistance.

Electrical conductivity is estimated in the SI system in Siemens (S), and electrical conductivity - in S/m; similarly, electrical resistance is expressed in ohms (Ohm), and electrical resistivity - in Ohm/m. Good electrical conductivity is necessary, for example, for current-carrying wires (copper, aluminum).

In the manufacture of electric heaters for devices and furnaces, alloys with high electrical resistance (nichrome, constantan, manganin) are required. As the temperature of a metal increases, its electrical conductivity decreases, and as it decreases, it increases.

Magnetic properties

Magnetic properties are characterized by absolute magnetic permeability or magnetic constant, i.e., the ability of metals to be magnetized. In SI units, the magnetic constant has the dimension Gn/m. Iron, nickel, cobalt and their alloys, called ferromagnetic, have high magnetic properties. Materials with magnetic properties are used in electrical equipment and for the manufacture of magnets.

Chemical properties

Chemical properties characterize the ability of metals and alloys to resist oxidation or combine with various substances: atmospheric oxygen, solutions of acids, alkalis, etc. The easier a metal combines with other elements, the faster it is destroyed. The chemical destruction of metals under the influence of an external aggressive environment on their surface is called corrosion.

Metals that are resistant to oxidation under high heat are called heat-resistant or scale-resistant. Such metals are used for the manufacture of parts that are operated in high temperature zones.

The resistance of metals to corrosion, scale formation and dissolution is determined by the change in the mass of the test samples per unit surface per unit time.

The chemical properties of metals are necessarily taken into account in the manufacture of certain products. This especially applies to products or parts operating in chemically aggressive environments.

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Source: http://osvarke.net/materialovedenie/fizicheskie-i-himicheskie-svojstva-metallov/

Common physical properties of metals

 Problem 757. 
What determines the common physical properties of metals?
Describe these properties. Solution:
The common physical properties of metals are due to their crystal lattice structure.
The structural unit of a metal crystal lattice is an atom.

Crystal lattices of metals are formed by positively charged cations, which are “immersed” in an electron gas. Valence electrons move almost freely within a metal crystal.

The electron gas compensates for the repulsive forces of positive ions and is the cause of the thermodynamic and mechanical stability of the metallic state.

The idea of ​​an electron gas allows us to explain the specific properties of the metallic state: electrical conductivity, thermal conductivity, metallic luster. The electrons of the electron gas easily move in the metal under the influence of potential differences. The high thermal conductivity of metals is due to the ability of electrons to transfer kinetic energy. Metallic luster is a consequence of the ability of electron gas to reflect light waves well.

The plasticity of metals is a manifestation of the ease of changing multicenter bonds. The multicenter nature of the bonds gives metals the ability to easily rearrange their crystal lattices while maintaining a large number of such bonds. As the temperature rises, in most metals a restructuring of the crystals and their lattice structure occurs.

High or low melting and boiling points of metals are determined by the strength of the metal bond. A measure of the strength of bonds in metals is the atomization energy - the energy required to convert 1 mole of metal into atomic vapor. This energy varies from 76.6 kJ/mol for cesium to 851 kJ/mol for tungsten.  

Metals are malleable, i.e. ability to stretch into wire or thin thread. In this case, the crystal lattice of the metal is not destroyed, the connection between cations is preserved, and the metal retains its structure.

Features of the structure of metals in the crystalline state

Problems 758.
Based on the molecular orbital (MO) method, explain the structural features of metals in the crystalline state.
Solution:
Metals have high electrical conductivity, and electrons serve as current carriers in metals. This suggests that metals contain “free” electrons that can move around the crystal under the influence of even weak electric fields.

At the same time, nonmetals in the crystalline state are usually insulators and, therefore, do not contain free electrons. The reasons for these differences can be explained on the basis of the molecular orbital method (MO method).  

According to the MO method, when two identical atoms interact, instead of two energetically equivalent initial atomic orbitals, two molecular orbitals are formed, corresponding to different energy levels.

If three atoms interact, and their valence orbitals noticeably overlap, then not two, but three molecular orbitals arise, equally belonging to all three atoms (delocalized orbitals) characterized by three different energy values.

With a sequential increase in the number of interacting atoms, the addition of each of them leads to the formation of another energy level and to further delocalization of molecular orbitals (i.e., to their distribution over a larger number of atoms); the total number of energy levels will be equal to the number of interacting atoms. A diagram of such a process is shown in Fig. 1.  

Rice.
1. Change in the energies of molecular orbitals With an increase in the number of reacting atoms

As this diagram shows, as the number of atoms increases, the number of allowed energy states increases, and the distances between neighboring energy levels decrease.

With a small number of interacting atoms, transferring an electron from any energy level to the next higher level requires the expenditure of relatively large amounts of energy.

But with a large number of atoms N (in a macroscopic crystal N is of the order of Avogadro’s number), neighboring levels differ so little that an almost continuous energy band is formed, and the transition of an electron to the nearest higher level can occur with the expenditure of negligible energy.

If such a nearby level is not occupied by electrons, then the electron located at the previous level behaves as if, due to the delocalization of the orbitals, it can move around the crystal with arbitrarily small energy influences. The band gap is determined by the type of crystal: metal, semiconductor or dielectric (Fig. 2.

The filling of MOs that make up the energy band with electrons occurs in the order of successive increases in energy. In this case, in accordance with the Pauli principle, each MO can accommodate two electrons.

Accordingly, there can be no more than 2N electrons in the s-band, no more than 6N electrons in the p-band, and no more than 10N electrons in the d-band.

A band completely filled with electrons is called valence. The band free of electrons and located in energy above the valence band is called the conduction band. The valence band and conduction band may or may not overlap each other. If these zones do not overlap with each other, then there is a bandgap width between them.  

 Rice. 2. Band structure of the metal.

In metals, the valence and conduction bands overlap. Thus, s- and p-metals have overlapping outer s- and p-orbitals. Since the number of electrons in these orbitals is less than twice the number of MOs, there are a large number of unoccupied MOs in the conduction band.

The energies of MOs in the conduction band differ relatively little from each other, so electrons with very slight excitations easily move from one MO to the next MO, which ensures electrical conductivity and thermal conductivity.

As the temperature increases, an increasing number of electrons move to vacant MOs in the conduction band, which leads to a decrease in the number of vacant MOs and, accordingly, to a decrease in electrical conductivity. In d-elements, ns-, np- and (n-1)d-bands overlap.

However, the d-band is relatively narrow, so we can assume that some of the d-electrons in metals are localized, i.e. Covalent bonds are formed between neighboring atoms and cause an increase in the melting point and mechanical strength of d-elements and especially elements in the middle and at the end of periods (IV-VIII groups).

Methods for extracting metals from ores

Problem 759 . Indicate the most important methods for extracting metals from ores.

Solution:

a) The most important method of extracting metals from ores is based on the reduction of their oxides with coal or carbon monoxide (II):

Cu2O + C = Cu + CO

For example, iron smelting is carried out by reducing iron ores with carbon monoxide (II):

Fe2O3 3CO = 2Fe + 3CO

b) When processing sulfide ores, the sulfides are first converted into oxides by roasting, and then the resulting oxides are reduced with coal, for example:

2ZnS + 3O2 = 2ZnO + 2SO2;
ZnO + C - Zn + CO.

c) Hydrometallurgical methods for extracting metals from ores in the form of their compounds in aqueous solutions with various reagents and subsequent extraction of the metal from the solution. For example, the extraction of gold from ores using solutions of potassium or sodium cyanide (1987 by P.R. Bagration):

4Au + 8NaCN + O2 + 2H2O = 4Na[Au(CN)2] + 4NaOH

Gold is isolated from the resulting solution using zinc:

2Na[Au(CN)2] + Zn = Na2[Zn(CN)4] + Au.

d) Method for reducing metal oxides with strong reducing agents. For metals that cannot be reduced by either coal or CO, stronger reducing agents are used, such as hydrogen, magnesium, aluminum, silicon, etc. The reduction of a metal from its oxide using another metal is called metallothermy, for example:

Cr2O3 + 2Al = Al2O3 + 2Cr.

e) Electrolysis method. Metals whose oxides are very strong (aluminum, magnesium, etc.) are obtained by electrolysis; they are obtained by electrolysis of the melts of their ores. To obtain alkali metals, electrolysis of molten salts is used; for example, potassium can be obtained by electrolysis of a sylvinite melt.

f) Method of roasting ore. To obtain some metals, the method of roasting ore is used. For example, obtaining mercury from cinnabar:

HgS + O2 = SO2 + Hg.

Source: http://buzani.ru/zadachi/khimiya-glinka/1254-obshchie-svojstva-metallov-zadachi-757-759

Metal: what it is, its physical properties, what it consists of

05Dec

articles

The discovery of common physical and chemical properties of metals and alloys led to widespread use of the material. Over time, scientists began to study its characteristics in detail, as well as create various metalworking methods that increase strength and improve the crystal lattice. At the moment, there are such compositions that are used in shipbuilding.

More and more areas of life cannot do without metal elements - from a household spoon or fountain pen to complex mechanical components and microcircuits. But ordinary people often do not understand what kind of substance we use and what features make it so widespread. In the article we will talk about this in detail.

What is it - metal

The ancient Greek word metallion just means “to dig out of the earth” - mined from rock ore. Currently, 96 pure values ​​and an unlimited number of alloys are known. All of them differ from non-metals in their increased strength properties and conductivity, which is why wires are made from them. At first glance, you can distinguish a metal sample from a stone or other one by its specific shine.

Basic chemical properties of metals

There are no general rules in this category, since they are all divided into many subgroups according to activity level - alkaline, actinides, semimetals and others. Many interact with water, almost all interact with oxygen (except gold and platinum), and oxidation occurs. The process takes place under normal conditions if there is a lot of click in the composition, only when heated - if not. Also, almost all elements react with sulfur and chlorine.

Signs

We list the features by which the average person can distinguish substances of this category from non-metals:

• fishing line
• Good conductivity of heat and electricity.
• Strength.
• Can be forged and welded.
• Crystalline body structure.
• High melting and crystallization temperatures.

Classification and types of metals

There are pure, single-component structures and alloys. The most classic example is the different types of steel. They differ according to GOST in accordance with the addition of alloying additives. The higher the carbon content, the stronger the material. There is also a generally accepted distinction; below we present the subtypes.

Black

They are mined from metal ore. In production they occupy 90% of all raw materials. Usually these are cast iron and steel. To change the characteristics, more or less amount of carbon and alloying additives are added: copper, silicon, chromium, nickel.

One of the very popular subspecies is stainless steel, which is distinguished by its shiny surface and unique properties - lightness, high strength and resistance to humidity and temperature changes.

What applies to non-ferrous metals

The second name is non-iron, that is, alloys do not contain iron, but consist of more expensive materials. Substances have different colors and have unique qualities:

• durability;
• long-term preservation of properties;
• the formation of an oxide film that prevents corrosion.

Thanks to this, certain varieties can be used in medicine, jewelry, the chemical industry, and in the manufacture of electrical wires. Non-ferrous metals include aluminum, zinc, tin, lead, nickel, chromium, silver, gold and others.

Copper and its alloys are popular metals

Copper ore was one of the first to be processed by man because it is subjected to the cold method of forging and stamping. Pliability has led to demand everywhere. Oxygen in the composition leads to a red tint. But decreasing the valency in various compounds will lead to yellow, green, blue color. Excellent thermal conductivity is considered an attractive quality - second only to silver, which is why it is used for wires. Connections can be:

• solid - in combination with iron, arsenic, zinc, phosphorus;
• with poor solubility with bismuth, lead;
• fragile - with sulfur or oxygen.

Metals include aluminum and alloys

Al was discovered in 1825 and is distinguished by its ease and simplicity in metalworking. It is made from bauxite, and the reserves of this rock are practically inexhaustible. Next, the element is combined in various proportions with copper, manganese, magnesium, zinc, and silicon. Less often with titanium, lithium, beryllium. Features depending on additives:

• good weldability;
• corrosion resistance;
• high fatigue strength;
• plastic.

It is used for the manufacture of jewelry, cutlery, as well as for glass melting, in the food and military industries, for the creation of rockets and for the production of hydrogen and heat in aluminum energy.

All about the metals magnesium, titanium and their alloys

Mg is the lightest substance of this group. It does not have strength, but it has advantages, for example, plasticity, chemical activity. Due to its high structural ability, it is added to compositions to increase weldability and ease of metalworking with a cutting knife. It must be taken into account that magnesium is very susceptible to rust.

Titanium has similar qualities - lightness, ductility, silver color. But the anti-corrosion film appears upon first contact with oxygen. Distinctive features are low thermal conductivity, electrical conductivity, and lack of magnetism. Metal containing titanium is a substance used in the aviation, chemical, and shipbuilding industries.

Anti-friction alloys

A characteristic feature of this group is its ease of use under mechanical stress. They create virtually no friction and also reduce it in other composites. Very often they act as a solid lubricant for components, for example, for bearings. The composition usually includes fluoroplastic, brass, bronze, iron graphite and babbit.

Soft

These are those whose metal bonds are weakened. For this reason, they have a lower melting and boiling point and simply become deformed. Sometimes you can make a dent with one finger press, or leave a scratch with your fingernail. These include: copper, silver, gold, bronze, lead, aluminum, cesium, sodium, potassium, rubidium and others. One of the softest is mercury; it is found in nature in a liquid state.

What does hard metal mean?

In nature, such ore is extremely rare. The rock is found in fallen meteorites. One of the most popular is chrome. It is refractory and can be easily processed into metal. Another element is tungsten. It melts very poorly, but when properly processed is used in lighting applications due to its heat resistance and flexibility.

Metal materials in the energy sector

We would not have such a developed electrical network and a lot of devices that consume electricity if a number of substances were not distinguished by the presence of free electrons, positive ions and high conductivity. Wires are made from lead, copper and aluminum. Silver would be great, but its rarity affects the cost, so it is rarely used.

Features of Ferrous Secondary Metals

This is waste that is generated as a result of one of the metalworking stages - forging, cutting. These could be scraps or shavings. They are sent to steel-smelting furnaces, but before that they must pass inspections in accordance with GOST. Scrap is called ferrous metal, it is distinguished into steel and cast iron according to price. Its use is in great demand instead of ore processing.

Alkaline earth alloys

These are solid substances that have high chemical activity. They are very rarely found in their pure form, but are used in compounds. Their importance cannot be overestimated from the point of view of human and animal anatomy. Magnesium and calcium are essential microelements.

Alkali metal concept

They are able to dissolve in water, forming an alkali. Due to its increased chemical activity (reaction occurs with violent action, ignition, release of gas, smoke) it is almost never found in nature. After all, at the external level there is only one electron, which is easily given to any substance. Hydroxides are very important in industry.

General characteristics of materials from the d- and f-families

These are transition elements that can be both oxidizing and reducing agents. Properties depend on the environment in which they are located. But there are also common ones:

• there are many electrons in the outer level;
• several oxidation states;
• increased valence;
• strength;
• ductility;
• ductility.

What are the side subgroups of metals in the periodic system?

In fact, these are varieties of the previous category - transitional elements. This is a line from scandium to zinc. They are often smelted and have virtually the same characteristics as the above materials from the d- and f-families.

Alloys

Pure ingots mined from ore are used as rarely as possible. This is due to both high cost and insufficiently good qualities (to correct it, carbon and alloying additives are added). Sometimes compounds occur in nature, and you just need to adjust the composition. The most famous:

• brass;
• bronze;
• steel;
• cast iron.

Comparison of properties

The second part of the elements in the periodic table is characterized by a variety of characteristics, so it is almost impossible to provide a complete summary table. We offer a table that shows 4 distinctive features:

Signs	Metals	Nonmetals
Position in P.S.	Under the diagonal boron-astatine	Above her
Atomic structure	Large atomic radius, pure electrons in the last layer - from 1 to 3	Small, from 4 to 7 - respectively
Physical properties	Electrical conductivity, thermal conductivity, gloss, malleability, plasticity, in terms of state of aggregation, mostly solid	Dielectrics, non-shiny, brittle, gases, liquids and volatile solids
Crystal lattices	Metal	Molecular, atomic
Chemical properties	Restorers	Oxidative (sometimes reduced)

We talked about metal, what kind of material it is, how it is used. If you need metalworking machines, order them from the Rosta company.

Source: http://rocta.ru/info/metall-chto-ehto-takoe-ego-fizicheskie-svojstva-iz-chego-sostoit/

Chemical and physical properties of non-metals:

The division of chemical elements into metals and non-metals is quite arbitrary. There is a small group of elements that, under certain conditions, behave in an atypical manner.

For example, aluminum can react not only with acids, like most metals, but also with alkalis, like non-metallic elements. And germanium, which is a non-metal, can conduct electricity like a typical metal.

In our article we will look at the physical and chemical properties of non-metals, as well as their use in industry.

Valence Level Formula

The differences in the characteristics of elements are based on the structure of their atoms. Nonmetals have 4 to 8 electrons in their last energy level, with the exception of hydrogen, helium and boron. Almost all non-metals belong to p-elements. For example, this is chlorine, nitrogen, oxygen. Helium and hydrogen, which are p-elements, do not obey this rule. The physical properties of nonmetals, as well as the ability to undergo chemical transformations, are determined by their location in the periodic table.

Place of nonmetals in the system of chemical elements

A change in the properties of atoms of non-metallic elements occurs with an increase in the atomic number. During the period, due to the increase in the charge of the nucleus, the atom contracts and its radius decreases. The oxidizing ability also increases, and the reducing properties of the elements weaken.

The physical properties of nonmetals, as well as the features of their interaction with other substances, depend on the structure of their external energy level. The ability of atoms to attract foreign electrons into their sphere of influence also depends on it. For example, in the second period from boron to fluorine, the electronegativity of nonmetals increases.

The most active among all non-metallic elements is fluorine. In its compounds, it holds foreign electrons the strongest, maintaining a -1 charge.

Physical properties of non-metals

Nonmetals exist in various states of aggregation. Thus, boron, carbon, phosphorus are solid compounds, bromine is a liquid, nitrogen, hydrogen, oxygen are gases. All of them do not conduct electricity, are less durable than metals, and have low thermal conductivity.

The type of crystal lattice also affects the physical properties of nonmetals. For example, compounds with a molecular lattice (iodine, sulfur, phosphorus) have low boiling and melting points, and are also volatile. The atomic crystalline structure is inherent in silicon and diamond.

These substances are very strong, their melting and boiling points are high.

Halogens

The elements located in the main subgroup of the seventh group of the periodic table are chemically the most active nonmetals. Their atoms have the same number of electrons -7 in the last energy level, which explains the similarity of their chemical characteristics.

https://www.youtube.com/watch?v=I0jnGDhMEOk

The physical properties of simple substances – non-metals – are different. Thus, fluorine and chlorine are in the gaseous phase, bromine is the liquid, and iodine is in the solid state. The activity of halogens in a group weakens with increasing charge of the atomic nucleus; fluorine is the most reactive among the halogens.

In terms of reactivity, it is only surpassed by oxygen, which is part of the chalcogen group. The strength of hydrogen compounds of halogens, aqueous solutions of which are acids, increases from fluorine to iodine, and the solubility of poorly soluble salts decreases. The special position of fluorine among the halogens also concerns its ability to react with water.

Halogen can decompose water to form various products: its own oxide F2O, ozone, oxygen and hydrogen peroxide.

Oxygen and its features

The element is the most abundant on Earth. Its content in the soil is more than 47%, and the mass of gas in the air is 23.15%. The general physical properties of non-metals, such as nitrogen, oxygen, hydrogen, which are in the gaseous state, are determined by the structure of their molecules.

They all consist of two atoms connected by covalent nonpolar bonds. In the oxygen atom, at the last energy level there are two free p-electrons. Therefore, the oxidation state of the element is usually -2, and in compounds with fluorine (for example, OF2) +2.

Oxygen is poorly soluble in water; at a temperature of -183 ⁰C it turns into an easily mobile blue liquid that can be attracted by a magnet. The element is represented by two simple substances: oxygen O2 and ozone O3. The characteristic smell of ozone can be felt in the air after a thunderstorm.

The substance is extremely aggressive, decomposes organic materials and oxidizes even passive metals such as platinum or gold. Most complex substances - oxides, salts, bases and acids - contain oxygen atoms in their molecules.

Sulfur is a typical non-metallic element

Source: https://www.syl.ru/article/377578/himicheskie-i-fizicheskie-svoystva-nemetallov

Properties of metals

Metals are a group of elements in the form of simple substances that have characteristic metallic properties, such as high thermal and electrical conductivity, positive temperature coefficient of resistance, high ductility, malleability and metallic luster. In this article, all properties of metals will be presented in the form of separate tables.

The properties of metals are divided into physical, chemical, mechanical and technological.

Physical properties of metals

Physical properties include: color, specific gravity, fusibility, electrical conductivity, magnetic properties, thermal conductivity, heat capacity, expansion when heated.

The specific gravity of a metal is the ratio of the weight of a homogeneous metal body to the volume of the metal, i.e. this is the density in kg/m3 or g/cm3.

The fusibility of a metal is the ability of a metal to melt at a certain temperature, called the melting point.

Electrical conductivity of metals is the ability of metals to conduct electric current; it is a property of a body or environment that determines the occurrence of electric current in them under the influence of an electric field.

 Electrical conductivity refers to the ability to conduct primarily direct current (under the influence of a constant field), in contrast to the ability of dielectrics to respond to an alternating electric field by oscillating bound charges (alternating polarization), creating an alternating current.

The magnetic properties of metals are characterized by: remanent induction, coercive force and magnetic permeability.

The thermal conductivity of metals is their ability to transfer heat from more heated particles to less heated ones. The thermal conductivity of a metal is determined by the amount of heat that passes through a metal rod with a cross section of 1 cm2 and a length of 1 cm for 1 second. at a temperature difference of 1°C.

The heat capacity of metals is the amount of heat absorbed by a body when heated by 1 degree. The ratio of the amount of heat absorbed by a body with an infinitesimal change in its temperature to this change in a unit mass of a substance (g, kg) is called specific heat capacity, 1 mole of a substance is molar (molar).

Expansion of metals when heated . All metals expand when heated and contract when cooled. The degree of increase or decrease in the original size of the metal with a change in temperature of one degree is characterized by the coefficient of linear expansion.

Chemical properties of metals

Chemical properties include oxidation, solubility and corrosion resistance.

Metal oxidation is the reaction of a metal combining with oxygen, accompanied by the formation of oxides (oxides). If we consider oxidation more broadly, then these are reactions in which atoms lose electrons and various compounds are formed, for example, chlorides, sulfides. In nature, metals are found mainly in an oxidized state, in the form of ores, so their production is based on the reduction processes of various compounds. The solubility of metals is their ability to form homogeneous systems with other substances - solutions in which the metal is in the form of individual atoms, ions, molecules or particles. Metals dissolve in solvents, which are strong acids and caustic alkalis. The most commonly used in industry are: sulfuric, nitric and hydrochloric acids, a mixture of nitric and hydrochloric acids (aqua regia), as well as alkalis - caustic soda and caustic potassium. The corrosion resistance of metals is their ability to resist corrosion.

Mechanical properties of metals

Mechanical - strength, hardness, elasticity, viscosity, plasticity.

The strength of a metal is its ability to resist external forces without breaking.

The hardness of metals is the ability of a body to resist the penetration of another, harder body into it.

The elasticity of metals is the property of a metal to restore its shape after the cessation of the action of external forces that caused a change in shape (deformation).

The toughness of metals is the ability of a metal to resist rapidly increasing (impact) external forces. Viscosity is the opposite property of brittleness.

Plasticity of metals is the property of a metal to deform without destruction under the influence of external forces and retain a new shape after the force ceases. Plasticity is the inverse property of elasticity.

Technological properties of metals

Technological ones include hardenability, fluidity, malleability, weldability, and machinability.

The hardenability of metals is their ability to obtain a hardened layer of a certain depth.

The fluidity of metals is the property of a metal in a liquid state to fill a casting mold and reproduce its outlines in a casting.

The malleability of metals is a technological property that characterizes their ability to be processed by deformation, for example, forging, rolling, stamping without destruction.

The weldability of metals is their ability to form a permanent joint during the welding process that meets the requirements determined by the design and operation of the product being manufactured.

The machinability of metals by cutting is their ability to change the geometric shape, dimensions, and surface quality due to mechanical cutting of the workpiece material with a cutting tool. The machinability of metals depends on their mechanical properties, primarily strength and hardness.

Modern methods of testing metals are mechanical tests, chemical analysis, spectral analysis, metallographic and radiographic analyses, technological tests, flaw detection. These tests provide an opportunity to gain insight into the nature of metals, their structure, composition and properties, as well as determine the quality of finished products.

Table “Properties of metals: Cast iron, Cast steel, Steel”

1. Ultimate tensile strength
2. Yield strength (or Rp 0.2);
3. Relative elongation of the sample at break;
4. Bending strength;
5. The bending strength is given for a cast steel sample;
6. The fatigue limit of all types of cast iron depends on the mass and cross-section of the sample;
7. Elastic modulus;
8. For gray cast iron, the modulus of elasticity decreases with increasing tensile stress and remains almost constant with increasing compressive stress.

Table "Properties of spring steel"

1. Ultimate tensile strength,
2. Relative reduction in the cross-section of the sample at rupture,
3. Bending strength;
4. Ultimate strength under alternating cyclic loading at N ⩾ 107,
5. Maximum stress at a temperature of 30°C and a relative elongation of 1 2% for 10 hours; for higher temperatures, see section “Methods of joining parts”,
6. see section “Methods of connecting parts”;
7. 480 N/mm2 for cold-worked springs;
8. Approximately 40% more for cold-worked springs

Table "Properties of non-ferrous metals"

1. Elastic modulus, reference data;
2. Ultimate tensile strength;
3. Yield strength corresponding to plastic deformation of 0.2%;
4. Bending strength;
5. Largest value;
6. For individual samples

Table "Properties of light alloys"

1. Ultimate tensile strength;
2. Yield strength corresponding to plastic deformation of 0.2%;
3. Bending strength;
4. Largest value;
5. Strength indicators are given for samples and for castings;
6. Indicators of ultimate bending strength are given for the case of plane loading

Table "Metal-ceramic materials (PM)1) for plain bearings"

1. In accordance with DIN 30 910, 1990 edition;
2. In relation to the bearing 10/16 g 10;
3. Carbon is contained mainly in the form of free graphite;
4. Carbon is contained only in the form of free graphite

Table “Properties of metal-ceramic materials (PM)1 for structural parts”

1. In accordance with DIN 30 910, 1990 edition;

Table “Properties of soft magnetic materials”

1. Data applies to magnetic rings only.

Table “Properties of soft magnetic ferrites”

1. Standardized values;
2. Loss of magnetic properties by the material depending on frequency at low magnetic flux density (B < 0.1 mT);
3. Loss of magnetic properties at high magnetic flux density; measured preferably at f = 25 kHz, V = 200 mT, Θ = 100°C;
4. Magnetic permeability in a strictly sinusoidal magnetic field; measured at f

Source: http://press.ocenin.ru/svojstva-metallov/

Properties of metals: chemical, physical, technological

Chemical properties of metals

Physical properties of metals

Mechanical properties of metals

Technological properties of metals

Interesting facts about metals

Metals, video

It is no secret that all substances in nature are divided into three states: solid, liquid and gaseous. And solid substances, in turn, are divided into metals and non-metals; this division is also reflected in the table of chemical elements of the great chemist D.I. Mendeleev. Our article today is about metals, which occupy an important place both in chemistry and in many other areas of our lives.

Chemical properties of metals

We all, one way or another, encounter chemistry in our daily lives. For example, during cooking, dissolving table salt in water is the simplest chemical reaction. Metals also enter into various chemical reactions, and their ability to react with other substances is their chemical properties.

Among the basic chemical properties or qualities of metals, one can distinguish their oxidability and corrosion resistance. When metals react with oxygen, they form a film, that is, they exhibit oxidizability.

Corrosion of metals occurs in a similar way - their slow destruction due to chemical or electrochemical interaction. The ability of metals to resist corrosion is called their corrosion resistance.

Physical properties of metals

Among the main general physical properties of metals are:

• Melting.
• Density.
• Thermal conductivity.
• Thermal expansion.
• Electrical conductivity.

An important physical parameter of a metal is its density or specific gravity. What it is? The density of a metal is the amount of substance contained in a unit volume of the material. The lower the density, the lighter the metal. Light metals are: aluminum, magnesium, titanium, tin. Heavy metals include such metals as chromium, manganese, iron, cobalt, tin, tungsten, etc. (in total there are more than 40 types).

The ability of a metal to change from a solid to a liquid state is called melting. Different metals have different melting points.

The rate at which heat is conducted in a metal when heated is called the thermal conductivity of the metal. And compared to other materials, all metals have high thermal conductivity; to put it simply, they heat up quickly.

In addition to thermal conductivity, all metals conduct electric current, although some do it better and some worse (this depends on the structure of the crystal lattice of a particular metal). The ability of a metal to conduct electric current is called electrical conductivity. Metals with excellent electrical conductivity are gold, aluminum and iron, which is why they are often used in the electrical industry and instrument making.

Mechanical properties of metals

The main mechanical properties of metals are their hardness, elasticity, strength, toughness and ductility.

When two metals come into contact, microdents can form, but a harder metal can withstand impacts more effectively. This resistance of the metal surface to external impacts is its hardness.

How does the hardness of a metal differ from its strength? Strength is the ability of a metal to resist destruction under the influence of any other external forces.

The elasticity of a metal refers to its ability to return to its original shape and size after the load that caused the deformation of the metal is removed.

The ability of a metal to change shape under external influence is called plasticity.

Technological properties of metals

The technological properties of metals and alloys are important primarily in their production, since the ability to undergo various types of processing in order to create a variety of products depends on them.

Among the main technological properties are:

• Ductility.
• Fluidity.
• Weldability.
• Hardenability.
• Cutting processing.

Malleability refers to the ability of a metal to change shape in hot and cold states. The malleability of metal was discovered in ancient times, so blacksmiths engaged in processing metal products, turning them into swords or plowshares (depending on need) for many centuries and historical eras were one of the most respected and sought-after professions.

The ability of two metal alloys to join together when heated is called weldability.

The fluidity of the metal is also very important; it determines the ability of the molten metal to flow over the prepared form.

The ability of a metal to harden is called hardenability.

Interesting facts about metals

• The hardest metal on Earth is chromium. This bluish-white metal was discovered in 1766 near Yekaterinburg.
• Conversely, the softest metals are aluminum, silver and copper. Due to their softness, they are widely used in various fields, for example, in electrical equipment manufacturing.
• Gold - which for centuries has been the most precious metal itself - has another interesting property - it is the most ductile metal on Earth, which also has excellent ductility and malleability. Also, gold does not oxidize at normal temperatures (to do this it needs to be heated to 100C), has high thermal conductivity and moisture resistance. Surely all these physical characteristics make real gold so valuable.
• Mercury is a unique metal, primarily in that it is the only metal that has a liquid form. Moreover, under natural conditions, mercury does not exist in solid form, since its melting point is -38C, that is, in a solid state it can exist in places where it is simply very cold. And at room temperature 18C, mercury begins to evaporate.
• Tungsten is interesting because it is the most refractory metal in the world; in order for it to start melting, a temperature of 3420C is needed. It is for this reason that in light bulbs the filaments that take the main heat shock are made of tungsten.

Metals, video

And finally, an educational video on the topic of our article.

Source: https://www.poznavayka.org/fizika/svoystva-metallov/

What properties do metals and alloys have?

Metal products and parts are used in various industries. There are many types of metals and each of them has strengths and weaknesses. When making parts for cars, airplanes or industrial equipment, craftsmen pay attention to the characteristics of the material. Therefore, it is required to know the properties of metals and alloys.

Properties of metals and alloys

Signs of metals

Metals have characteristics that characterize them:

1. High thermal conductivity. Metal materials conduct electricity well.
2. Shine on a break.
3. Ductility.
4. Crystal structure.

Not all materials are durable and have high wear resistance. The same applies to melting at high temperatures.

Metal classification

Metals are divided into two large groups - ferrous and non-ferrous. Representatives of both species differ not only in characteristics, but also in appearance.

Colored

Representatives of this group are distinguished by their bright color, lower strength, hardness and melting point (not for everyone). This group is divided into the following subgroups:

1. Light - a subgroup that includes metals with a density of up to 5000 kg/m3. These are materials such as lithium, sodium, potassium, magnesium and others.
2. Heavy - this includes silver, copper, lead and others. Density exceeds 5000 kg/m3.
3. Noble - represented in this subgroup have a high cost and resistance to corrosion processes. These include gold, palladium, iridium, platinum, silver and others.

Refractory and low-melting metals are distinguished.
Tungsten, molybdenum and niobium are refractory, and all the rest are low-melting. Classification of substances. Metals | Chemistry 11th grade #20 | Info lesson

Main types of alloys

Humanity is familiar with various metal alloys. The most numerous of them are iron-based compounds. These include ferrites, steels and cast iron. Ferrites are magnetic, cast iron contains more than 2.4% carbon, and steel is a material with high strength and hardness.

Metal alloys made of non-ferrous metals require special attention.

Zinc alloys

Compounds of metals that melt at low temperatures. Zinc-based mixtures are resistant to corrosive processes. Easy to process.

Aluminum alloys

Aluminum and alloys based on it gained popularity in the second half of the 20th century. This material has the following advantages:

1. Low temperature resistance.
2. Electrical conductivity.
3. Light weight of workpieces compared to other metals.
4. Wear resistance.

However, we must not forget that aluminum melts at low temperatures. At temperatures around 200 degrees, performance deteriorates.

Aluminum is used in the manufacture of components for machines, the production of parts for aircraft, components of industrial equipment, utensils, and tools. Not many people know that aluminum is popular in the production of weapons. This is due to the fact that aluminum parts do not spark under strong friction.

To increase the strength of the part, aluminum is mixed with copper.
So that the workpiece can withstand pressure - with manganese. Silicon is added to make a regular casting. Aluminum. Aluminum alloys. Aluminum bicycle frames.

Copper alloys

Copper-based alloys are grades of brass. High precision parts are made from this material, as brass is easy to process. The alloy may contain up to 45% zinc.

Properties of alloys

To manufacture parts and structures, you need to know the basic properties of metals and alloys. If processed incorrectly, the finished part can quickly fail and destroy the equipment.

Internal combustion engine

Mechanical properties

The mechanical properties of metals and alloys are responsible for the integrity of the material structure:

• strength;
• hardness;
• plastic;
• viscosity;
• fragility;
• resistance to mechanical loads.

Technological properties

Technological properties determine the ability of a metal or alloy to change during processing:

1. Ductility. Pressure processing of the workpiece. The material is not destroyed. The structure is changing.
2. Weldability. Susceptibility of the part to work with welding equipment.
3. Shrinkage. This process occurs when the workpiece is cooled after it has been heated.
4. Processing with cutting tools.
5. Liquation (solidification of liquid metal with decreasing temperature).

The main method of processing metal parts is heating.

The properties of metals and alloys are responsible for how the finished product will behave during operation.
When processing materials, it is also important to know its characteristics. Chemistry 48. Properties of metals and alloys. Combustion catalysts – Academy of Entertaining Sciences

What properties do metals and alloys have? Link to main publication

Source: https://metalloy.ru/splavy/i-metally-svojstva

Physical and chemical properties of metals

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 (Fe3O4, Fe2O3, (NaK)2O×AlO3), salts (KCl, BaSO4, Ca3(PO4 )2), and also accompany various minerals (Cd – zinc ores, Nb, Tl – tin ores, etc.).

Obtaining metals

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

2NaCl = 2Na + Cl2

CaCl2 = Ca + Cl2

2Al2O3 = 4Al + 3O2

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):

Cu2O + C = 2Cu + CO (1)

CuSO4 + Fe = Cu + FeSO4 (2)

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

Ni(CO)4 = Ni + 4CO

Examples of problem solving

Source: http://ru.solverbook.com/spravochnik/svojstva-po-ximii/fizicheskie-i-ximicheskie-svojstva-metallov/