What properties does metal have?

Change of metallic and non-metallic properties in the periodic table

The periodic table of Dmitry Ivanovich Mendeleev is very convenient and universal in its use. Using it, you can determine some characteristics of elements, and, most surprisingly, predict some properties of chemical elements that have not yet been discovered by scientists (for example, we know some of the properties of the supposed unbihexium, although it has not yet been discovered or synthesized).

What are metallic and non-metallic properties

These properties depend on the element's ability to donate or attract electrons. It is important to remember one rule: metals give up electrons, and non-metals accept them. Accordingly, metallic properties are the ability of a certain chemical element to give up its electrons (from the external electron cloud) to another chemical element. For non-metals, the opposite is true. The more easily a nonmetal accepts electrons, the higher its nonmetallic properties.

Metals will never accept electrons from another chemical element. This is typical for the following elements;

• sodium;
• potassium;
• lithium;
• France and so on.

The situation is similar with non-metals. Fluorine exhibits its properties more than all other non-metals; it can only attract particles of another element to itself, but under no circumstances will it give up its own. It has the greatest non-metallic properties . Oxygen (according to its characteristics) comes immediately after fluorine. Oxygen can form a compound with fluorine, donating its electrons, but it takes away negative particles from other elements.

List of non-metals with the most pronounced characteristics:

1. fluorine;
2. oxygen;
3. nitrogen;
4. chlorine;
5. bromine.

Non-metallic and metallic properties are explained by the fact that all chemical substances strive to complete their energy level. To do this, the last electronic level must have 8 electrons. The fluorine atom has 7 electrons in its last electron shell, and in an effort to complete it, it attracts one more electron. The sodium atom has one electron on its outer shell, to get 8, it is easier to give it 1, and at the last level there will be 8 negatively charged particles.

Noble gases do not interact with other substances precisely because their energy level is completed; they do not need to attract or give up electrons.

How metallic properties change in the periodic table

Mendeleev's periodic table consists of groups and periods. The periods are arranged horizontally in such a way that the first period includes: lithium, beryllium, boron, carbon, nitrogen, oxygen, and so on. Chemical elements are arranged strictly according to increasing atomic number.

The groups are arranged vertically in such a way that the first group includes: lithium, sodium, potassium, copper, rubidium, silver, and so on. The group number indicates the number of negative particles at the external level of a certain chemical element. While the period number indicates the number of electron clouds.

Metallic properties increase in a row from right to left or, in other words, weaken in a period. That is, magnesium has greater metallic properties than aluminum, but less than sodium. This happens because during a period the number of electrons in the outer shell increases, therefore, it is more difficult for the chemical element to give up its electrons.

In the group, everything is the other way around, the metallic properties increase in the row from top to bottom. For example, potassium appears stronger than copper, but weaker than sodium. The explanation for this is very simple: the number of electron shells in a group increases, and the further the electron is from the nucleus, the easier it is to give it away to the element. The force of attraction between the nucleus of an atom and the electron in the first shell is greater than between the nucleus and the electron in the 4th shell.

Let's compare two elements - calcium and barium. Barium has a lower value in the periodic table than calcium. This means that the electrons from the outer shell of calcium are located closer to the nucleus, therefore, they are better attracted than those of barium.

It is more difficult to compare elements that are in different groups and periods. Take calcium and rubidium, for example. Rubidium will give off negative particles better than calcium. Since he stands lower and to the left.

But using only the periodic table, it is impossible to unambiguously answer this question by comparing magnesium and scandium (since one element is lower and to the right, and the other is higher and to the left).

To compare these elements, you will need special tables (for example, the electrochemical series of metal voltages).

How do nonmetallic properties change in the periodic table?

Non-metallic properties in the periodic table of Mendeleev change exactly the opposite way than metallic ones. Essentially, these two characteristics are antagonists.

Non-metallic properties increase in period (in a row from right to left). For example, sulfur can attract electrons less than chlorine, but more than phosphorus. The explanation for this phenomenon is the same. The number of negatively charged particles on the outer layer increases, and therefore it is easier for the element to finish its energy level.

Non-metallic properties decrease from top to bottom (in a group). For example, phosphorus is able to release negatively charged particles more than nitrogen, but at the same time it is able to attract better than arsenic. Phosphorus particles are attracted to the nucleus better than arsenic particles, which gives it the advantage of an oxidizing agent in reactions to decrease and increase the oxidation state (redox reactions).

Let's compare, for example, sulfur and arsenic . Sulfur is higher and to the right, which means it is easier for it to complete its energy level. Like metals, nonmetals are difficult to compare if they are in different groups and periods.

For example, chlorine and oxygen. One of these elements is higher and to the left, and the other is lower and to the right.

To answer, we will have to refer to the table of electronegativity of non-metals, from which we see that oxygen attracts negative particles more easily than chlorine.

Mendeleev's periodic table helps to find out not only the number of protons in an atom, atomic mass and atomic number, but also helps to determine the properties of elements.

will help you understand the patterns of properties of chemical elements and their compounds by periods and groups.

Source: https://LivePosts.ru/articles/education-articles/himiya/usilenie-metallicheskih-i-nemetallicheskih-svojstv-v-tablitse

How metals differ from non-metals - features, properties and characteristics:

In everyday life, a person interacts with many substances. All elements can be classified according to physical and chemical qualities. In the article we will look at how metals differ from non-metals, their properties and concept.

Definition of metal and its properties

Every day we deal with metals and this is not without reason. Most elements of the periodic table are them. They all have their own characteristics and properties.

As a rule, metals are elements that conduct heat and electricity well. Metals are also very ductile, which allows them to change their shape by forging, and they also have a high hardness coefficient. A distinctive feature of this element is its luster, which is called metallic. The properties of the metal are divided into two main fractions, such as:

• Physical properties.
• Chemical properties.

How do metals differ from metals in physical characteristics? Physical properties include:

• Color. Metals, as a rule, have a dense structure that does not allow light to pass through. And their color is determined by the reflection of light from its surface. Thus, metals in most cases have colors ranging from gray to silver. But there are exceptions, such as copper, which is red, and gold, which is yellow.
• State of shape, hardness and density. Metals themselves have a solid state of aggregation, but are capable of turning into liquid at high temperatures. Thus, metals melt at temperatures from 40 to 3400 degrees Celsius. But there are metals whose main state of aggregation is liquid. These elements include mercury.
• Electrical conductivity. A special feature is its decrease with increasing temperature of the substance.
• Thermal conductivity and boiling/melting point.

How do metals differ from metals in chemical properties? This group includes:

• Oxidability. Metals also oxidize, and the oxide film on the surface can give them a different shade.
• Reaction with non-metals, acids, water, salts.

How do metals differ from each other?

Many people do not know how metals differ from metals. Their differences can be classified:

• Metals differ in color from each other, such as gold and copper.
• Metals also melt at different temperatures. Some metals, such as tin and lead, can be melted at home, but others require higher temperatures.
• Metals are divided into two groups: heavy and light. Heavy metals include those whose density is from 5 g/cm3, light metals have a density less than 5 g/cm3. Light metals include lithium, which has a density of 0.2 g/cm3; the place of the heaviest metal is shared by osmium and iridium. Their density is 22.6 g/cm3.
• Metals differ from each other in ductility and electrical conductivity. Some of them are very flexible. For example, from just 1 gram of gold you can make a thin wire of 3.5 kilometers. It will be flexible and will not break. It will not be possible to repeat this with a less ductile metal.
• Also, some metals conduct current better than others. The most electrically conductive metals are copper, silver and aluminum. They are most often used as conductive elements.

How do nonmetals differ from metals?

Non-metals are commonly called elements that have non-metallic properties. How do metals differ from non-metals? Let's take a closer look:

• Form. So non-metals have three states of aggregation: liquid, solid and gaseous.
• Electrical conductivity. Nonmetals do not conduct current like metals and have lower thermal conductivity.
• Visual differences. Metal is easy to distinguish visually from non-metal, since the former has a metallic sheen. Nonmetals include elements such as bromine, sulfur and hydrogen.
• Chemical structure. It is also easy to distinguish them by their structure. Metals have a clear crystal lattice. Nonmetals have an ionic structure.
• Entry into reactions. Nonmetals have a larger number of unoccupied electrons located in outer levels. This is what allows them to have a high oxidizing capacity compared to metals.

How is wood similar to metal and what are their differences?

Wood is a plant material. Metal is the result of a natural chemical compound. What is the difference between wood and metal:

• Wood does not conduct electricity and ignites at a fairly low temperature compared to metals.
• Wood does not melt when exposed to high temperatures.
• Wood also conducts heat poorly, unlike metals.
• Wood is elastic, but not flexible. Metals have a lower elasticity coefficient, but they are more ductile. This way you can easily fold the wire in half without breaking it; the wood will break in half under this impact.
• Another distinguishing feature of wood from metal is that it does not corrode. There are wood species that can remain in water for a long time without rotting. Under such conditions, metals become covered with rust.
• The density of wood is quite low compared to metals. Although some metals have a density lower than wood, they are classified as light metals.

How do semiconductors differ from metals?

Semiconductors are non-metals that have some metallic properties. Metals and semiconductors are similar in that both are capable of conducting current.

But semiconductors have a distinctive feature, which is that their electrical conductivity can increase several times depending on external factors. Thus, a semiconductor conducts current better as the temperature increases. In metals, electrical conductivity decreases with increasing temperature. The electrical conductivity can also be affected by the presence of foreign impurities. Thus, in metals, impurities reduce electrical conductivity, and in semiconductors they increase.

Semiconductors, unlike metals, can have positive and negative electrical conductivity. Semiconductors themselves, in terms of their ability to pass current through themselves, stand between metal and elements that do not conduct current at all.

The difference between metal and steel

It is a mistake to think that metal and steel are completely different elements. In fact, steel is also a metal. What is the difference between metal and steel?

The fact is that metals are a whole group of elements that have metallic properties. This group also includes iron. Steel is nothing more than an alloy of iron with elements belonging to the group of metals.

Most often, in addition to iron, steel contains elements of the periodic table such as molybdenum, chromium and vanadium. Steel also contains carbon. It is used to increase the strength of iron.

Thus, by varying the amount of carbon in the alloy, a very strong material can be obtained. But the stronger the steel, the more brittle it becomes. Thus, under prolonged dynamic load, steel breaks easily. Adding other impurities to it helps to achieve resistance to any influences.

So, the article examined how metals differ from metals and non-metals. The characteristics of all elements can be compared in terms of chemical and physical properties. Every day a person uses such elements and creates new substances to improve the quality of life.

Source: https://www.syl.ru/article/372332/chem-metallyi-otlichayutsya-ot-nemetallov---osobennosti-svoystva-i-harakteristiki

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/

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/

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

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/

Non-metals. Physical and chemical properties

How can one determine whether a substance is a metal or a non-metal?

If you look closely at the Periodic Table of D.I. Mendeleev (we get acquainted with the classification of elements in detail in paragraph 42 of the chemistry textbook for the 8th grade, edited by V.V. Eremin) and draw a conditional diagonal from hydrogen through boron to astatine and the yet undiscovered element No. 118, the table of non-metals will occupy the upper right corner.

Each horizontal period of the table ends with an element with a completed external energy level. This group of elements is called noble gases and has special properties, which can be found in paragraph 18 of the textbook “Chemistry” for grade 8, edited by V.V. Eremin.

When considering the electronic structure of nonmetals, you can notice that the energy levels of an atom are filled with electrons by more than 50% (the exception is boron), and for elements located in the table from right to left, the number of electrons at the outer level increases. Therefore, in chemical reactions, this group of substances can be both an electron acceptor with oxidizing properties and an electron donor with reducing properties.

The substances that form the boron-silicon-germanium-arsenic-tellurium diagonal are unique and, depending on the reaction and reagent, can exhibit both metallic and non-metallic properties. They are called metalloids. In chemical reactions they exhibit predominantly reducing properties.

Physical properties of nonmetals. Allotropy

If you look at metals, then with the naked eye you can notice general properties - metallic luster, solid state of aggregation (with the exception of liquid mercury), thermal and electrical conductivity.

With non-metals everything is much more complicated. They can have a molecular and non-molecular structure. Due to differences in structure, simple nonmetal substances exist in three states of aggregation:

1. Molecular:
   • Volatile, gaseous, colorless oxygen, hydrogen.
   • Gaseous, colored chlorine, nitrogen, fluorine.
   • The only liquid representative is dark red bromine.
   • Solid but brittle substances with a low melting point - crystals of iodine, sulfur, white phosphorus.
2. Non-molecular:
   • Solids with a high melting point are silicon, graphite, diamond and red phosphorus.

Most non-metallic substances are poor conductors of electricity and heat.

The exception is graphite, a type of carbon.

Allotropy is the unique ability of a nonmetallic element to form several simple substances. In the natural environment, there are allotropic modifications of elements that differ in physical and chemical properties. These include ozone and oxygen, graphite and diamond. You can learn more about the physical properties of nonmetals in the textbook “Chemistry. 9th grade."

Chemical properties of non-metals

As we discussed above, the group of nonmetals is quite polymorphic and, depending on the type of reactions in which they participate, they can exhibit both oxidizing and reducing properties. Fluorine is an exception in this series. It is always an oxidizing agent.

In the series F, O, N, CL, Br, I, S, C, Se, P, As, Si, H, the oxidizing properties decrease. Oxygen can exhibit reducing properties only in relation to fluorine.

In this type of reaction, oxidizing properties occur and nonmetals accept electrons to form negatively charged species.

Ca + Cl2 = CaCl2

Ca + O2 = CaO2

Na + Cl2 = Na+Cl2

Almost all non-metals react with hydrogen. Only noble gases are an exception for reactions of this type. The reaction product is volatile hydrogen compounds:

Cl2 + H2 = 2HCl

C + 2H2 = CH4

Nonmetals form acidic or non-salt-forming oxides.
S + O2 = SO2

P + 5O2 = 2P2O5

    4. Interaction with water and acids is not typical for non-metals.

What else should I read?

OGE in Chemistry - 2019: schedule, assessment criteria, types of tasks
Biography of D.I.
Mendeleev. Interesting facts from the life of the great chemist Carboxylic acids Mass fraction of the substance

History of the discovery of nonmetals

Copper utensils, iron tools, gold jewelry - people have long noticed that all these substances have certain common properties:

• they conduct heat and electricity;
• they are characterized by a metallic luster;
• due to their plasticity and malleability, they can be given any shape;
• All substances are characterized by a metallic crystal lattice.

In contrast to metals, there were other substances that did not have metallic properties, and were accordingly called nonmetals. Almost until the end of the 17th century, alchemical scientists knew only two non-metallic substances - carbon and sulfur.

In 1669, Brand, in search of the “philosopher’s stone,” discovered white phosphorus. And in a short period from 1748 to 1798, about 15 new metals and 5 non-metals were discovered.

Attempts to discover fluorine cost researchers not only their health, but also their lives. Devi, the Knox brothers, Gay-Lussac - this is an incomplete list of victims of science who lost their health in attempts to isolate fluorine from fluorspar. It was only in 1886 that Moissan solved a difficult problem using electrolysis. And he received the first halogen, and also poisonous chlorine. During the First World War it was used as a weapon of mass destruction.

Currently, 22 non-metallic elements have been discovered.

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Source: https://rosuchebnik.ru/material/nemetally/

Steel 

Steel belongs to ferrous metals. Carbon steel, which is an alloy of iron with carbon and other elements, is best suited for artistic processing. Steel has high quality characteristics, including the following:

• Elasticity
• Strength
• Hardening ability - a piece of steel is heated at a high temperature until red-hot and then dipped in water. Thanks to this, the metal acquires varying degrees of hardness and elasticity.
• Possibility of “releasing” by heating to red heat and then slowly cooling.
• Ability to be processed with a forging hammer in a heated state, since the steel is perfectly forged.
• Possibility of cutting metal into thin strips.

The softness of steel is directly proportional to the amount of carbon in its composition. The less carbon there is in a metal, the softer and easier it is to process. The softness of steel increases during annealing, that is, “releasing” the metal. To do this, the steel is heated red-hot and then subjected to a slow cooling procedure.

Steel for the manufacture of various products and artistic processing is produced in the form of graded material. For engraving and minting, U8 and U10 steels are most often used, where the letter “U” indicates the amount of carbon in the alloy.

The blade of the knives is made of stainless carbon steel

Non-ferrous metals

Non-ferrous metals are much more expensive than ferrous metals because they have many unique properties. The main one is the lack of reaction with a magnet, that is, non-ferrous metals are not attracted and are not magnetized. In addition, most of them are practically resistant to oxidation, so the products are characterized by a long service life.

The production of non-ferrous metals for artistic processing is carried out in various forms:

• Ribbons
• Stripes
• Chushki
• Tubes
• Wire
• Rods
• Sheets

Let's look at the characteristic features of the most popular non-ferrous metals among craftsmen:

• Copper is a fairly soft metal of a beautiful red-orange hue, characterized by increased ability to forge and has high electrical conductivity and the ability to conduct heat. Processing copper is not particularly difficult, but the craftsman must keep in mind the high viscosity of this metal.

Copper can be soldered using tin and braze. Copper sheet is the main material for chasing and engraving work. Copper wire is used to make decorative items and openwork sculptures.

Copper sink

• Bronze is an alloy of copper and tin. The quantitative tin content affects the color of the alloy, which can take on pink, red, yellow or gray shades. If a bronze product is covered with a layer of patina (a decorative coating of copper oxide), then it acquires a noble smoky-greenish tint and looks ancient and truly expensive. Bronze is most often used for inlay and foundry work.

Sheet bronze

• Brass is an alloy of copper and zinc. The shade of the metal depends on the amount of zinc. According to its qualitative characteristics, brass is a harder alloy than pure red copper, therefore its degree of malleability is much lower. Compared to copper, brass has some brittleness, but at the same time it is more elastic.

Brass can easily be processed in various ways; in particular, it can be used for the manufacture of thin parts in inlays, as well as jewelry of various configurations. For embossing work it is used in sheet form.

Embossing on brass

• Zinc is perfect for casting both in its pure form and in alloys with other metals. Pure zinc is difficult to forge, but it is easy to solder, engrave, and machine with a variety of tools. The melting point is 419* C.

Sheet zinc

• Tin is a non- ferrous metal, known for a long time for its softness and ductility. Its melting point is only 252* C. As a component, tin is included in various types of bronze. When broken, tin produces a characteristic, recognizable crunch. Pure tin and its alloys are ideal for making inlays. Tin is also used for tinning and soldering dishes, both in its pure form and in alloys with lead. At the same time, its oxidation products are harmless.

Set of tin soldiers

• Aluminum is a silvery-white non-ferrous metal that melts at a temperature of about 658* C. A characteristic feature of aluminum is its lightness and ease of metal processing. Cast aluminum is quite brittle, but when rolled (annealed) it acquires the desired ductility.

Aluminum crafts from Madagascar

• Lead is a soft non-ferrous metal with a bluish-gray tint. It melts at a temperature of 327* C and resists corrosion well. However, it should be noted that lead oxides are poisonous. Lead is suitable for foundry work and the manufacture of molded products.

Lead (standard)

• Silver is also a non-ferrous metal, but it is also a precious metal. Pure silver is too soft and therefore difficult to work with. For the manufacture of products it is used in the form of alloys with copper. Silver inserts are used in inlays, engraving, embossing and niello.

Antique silver items

Let's consider some properties of metals that affect the quality of artistic products:

• Malleability of the metal - Malleable ductile metals require greater cutting force, but their toughness must be taken into account. A piece of copper or lead needs to be chopped to the end, but brass, zinc or steel can be chipped with a chisel and then simply broken. Harder brass gives a smooth surface when turned, while aluminum or copper seems to drag on the cutter.
• Brittleness is the ability of solid materials to fracture due to mechanical stress without noticeable plastic deformation. This property is the opposite of plasticity. Heavily hardened steel, as well as many types of brass and bronze, are very brittle and will break into pieces under strong impacts. The brittleness of a metal is not always a sign of its hardness; for example, a zinc casting is brittle but not hard. A hardened steel knife is both hard and brittle.
• Elasticity is the property of metals to restore their shape and volume after the cessation of external forces or heating that caused the deformation. To a large extent, special grades of steel have this property.
• Melting when heated - the ability of a metal to melt when heated is an important quality, since melting is considered one of the most accessible and cheapest ways to produce metal products. Parts of huge machines and small metal sculptures are made in the same way.

If there is a need to harden a part while maintaining the viscosity of the metal, craftsmen use high-frequency currents. In this case, the part is hardened to a depth of several millimeters. However, the rest of the metal mass inside the product remains unchanged. And finally, metal parts can be processed without heating - for example, by engraving and metal carving.

Silver products

Source: http://design-fly.ru/materiali/svojstva-metallov.html

General physical and chemical 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.

1. 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

2. 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

3. 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.

4. 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 in 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”.