What crystal lattice does solid sodium hydroxide have? Types of crystal lattices

It is not individual atoms or molecules that enter into chemical interactions, but substances. Substances are classified according to the type of bond molecular and non-molecular buildings.

These are substances made up of molecules. The bonds between the molecules in such substances are very weak, much weaker than between the atoms inside the molecule, and even at relatively low temperatures they break - the substance turns into a liquid and then into a gas (sublimation of iodine). The melting and boiling points of substances consisting of molecules increase with increasing molecular weight. Molecular substances include substances with an atomic structure (C, Si, Li, Na, K, Cu, Fe, W), among them there are metals and non-metals.

Non-molecular structure of substances

To substances non-molecular structures include ionic compounds. Most compounds of metals with non-metals have this structure: all salts (NaCl, K 2 S0 4), some hydrides (LiH) and oxides (CaO, MgO, FeO), bases (NaOH, KOH). Ionic (non-molecular) substances have high melting and boiling points.

Solids: crystalline and amorphous

Amorphous substances they do not have a clear melting point - when heated, they gradually soften and turn into a fluid state. For example, plasticine and various resins are in an amorphous state.

Crystalline substances characterized by the correct arrangement of the particles of which they consist: atoms, molecules and ions - at strictly defined points in space. When these points are connected by straight lines, a spatial frame is formed, called crystal lattice. The points at which crystal particles are located are called lattice nodes.

Depending on the type of particles located at the nodes of the crystal lattice and the nature of the connection between them, four types of crystal lattices are distinguished: ionic, atomic, molecular and metallic .

Ionic crystal lattices

Ionic are called crystal lattices, in the nodes of which there are ions. They are formed by substances with ionic bonds, which can bind both simple ions Na +, Cl -, and complex S0 4 2-, OH -. Consequently, salts and some oxides and hydroxides of metals have ionic crystal lattices. For example, a sodium chloride crystal is built from alternating positive Na + and negative Cl - ions, forming a cube-shaped lattice.

Ionic crystal lattice of table salt

The bonds between ions in such a crystal are very stable. Therefore, substances with an ionic lattice are characterized by relatively high hardness and strength, they are refractory and non-volatile.

Atomic crystal lattices

Atomic are called crystal lattices, in the nodes of which there are individual atoms. In such lattices, the atoms are connected to each other by very strong covalent bonds. An example of substances with this type of crystal lattices is diamond, one of the allotropic modifications of carbon.

Atomic crystal lattice of diamond

Most substances with an atomic crystal lattice have very high melting points (for example, for diamond it is over 3500 ° C), they are strong and hard, and practically insoluble.

Molecular crystal lattices

Molecular called crystal lattices, in the nodes of which molecules are located.

Molecular crystal lattice of iodine

Chemical bonds in these molecules can be both polar (HCl, H 2 O) and non-polar (N 2, O 2). Despite the fact that the atoms inside the molecules are connected by very strong covalent bonds, weak intermolecular forces of attraction act between the molecules themselves. Therefore, substances with molecular crystal lattices have low hardness, low melting points, and are volatile. Most solid organic compounds have molecular crystal lattices (naphthalene, glucose, sugar).

Metal crystal lattices

Substances with metallic bonds have metal crystal lattices.

At the sites of such lattices there are atoms and ions (either atoms or ions, into which metal atoms easily turn, giving up their outer electrons “for common use”). This internal structure of metals determines their characteristic physical properties: malleability, ductility, electrical and thermal conductivity, characteristic metallic luster.

As we already know, a substance can exist in three states of aggregation: gaseous, hard And liquid. Oxygen, which under normal conditions is in a gaseous state, at a temperature of -194 ° C is transformed into a bluish liquid, and at a temperature of -218.8 ° C it turns into a snow-like mass with blue crystals.

The temperature range for the existence of a substance in the solid state is determined by the boiling and melting points. Solids are crystalline And amorphous.

U amorphous substances there is no fixed melting point - when heated, they gradually soften and turn into a fluid state. In this state, for example, various resins and plasticine are found.

Crystalline substances They are distinguished by the regular arrangement of the particles of which they consist: atoms, molecules and ions, at strictly defined points in space. When these points are connected by straight lines, a spatial framework is created, it is called a crystal lattice. The points at which crystal particles are located are called lattice nodes.

The nodes of the lattice we imagine can contain ions, atoms and molecules. These particles perform oscillatory movements. When the temperature increases, the range of these oscillations also increases, which leads to thermal expansion of bodies.

Depending on the type of particles located at the nodes of the crystal lattice and the nature of the connection between them, four types of crystal lattices are distinguished: ionic, atomic, molecular And metal.

Ionic These are called crystal lattices in which ions are located at the nodes. They are formed by substances with ionic bonds, which can bind both simple ions Na+, Cl-, and complex SO24-, OH-. Thus, ionic crystal lattices have salts, some oxides and hydroxyls of metals, i.e. those substances in which an ionic chemical bond exists. Consider a sodium chloride crystal; it consists of positively alternating Na+ and negative CL- ions, together they form a cube-shaped lattice. The bonds between ions in such a crystal are extremely stable. Because of this, substances with an ionic lattice have relatively high strength and hardness; they are refractory and nonvolatile.

Atomic Crystal lattices are those crystal lattices whose nodes contain individual atoms. In such lattices, atoms are connected to each other by very strong covalent bonds. For example, diamond is one of the allotropic modifications of carbon.

Substances with an atomic crystal lattice are not very common in nature. These include crystalline boron, silicon and germanium, as well as complex substances, for example those containing silicon (IV) oxide - SiO 2: silica, quartz, sand, rock crystal.

The vast majority of substances with an atomic crystal lattice have very high melting points (for diamond it exceeds 3500 ° C), such substances are strong and hard, practically insoluble.

Molecular These are called crystal lattices in which molecules are located at the nodes. Chemical bonds in these molecules can also be polar (HCl, H 2 0) or non-polar (N 2, O 3). And although the atoms inside the molecules are connected by very strong covalent bonds, weak forces of intermolecular attraction act between the molecules themselves. That is why substances with molecular crystal lattices are characterized by low hardness, low melting point, and volatility.

Examples of such substances include solid water - ice, solid carbon monoxide (IV) - “dry ice”, solid hydrogen chloride and hydrogen sulfide, solid simple substances formed by one - (noble gases), two - (H 2, O 2, CL 2 , N 2 , I 2), three - (O 3), four - (P 4), eight-atomic (S 8) molecules. The vast majority of solid organic compounds have molecular crystal lattices (naphthalene, glucose, sugar).

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Most substances are characterized by the ability, depending on conditions, to be in one of three states of aggregation: solid, liquid or gaseous.

For example, water at normal pressure in the temperature range 0-100 o C is a liquid, at temperatures above 100 o C it can only exist in a gaseous state, and at temperatures below 0 o C it is a solid.
Substances in the solid state are divided into amorphous and crystalline.

A characteristic feature of amorphous substances is the absence of a clear melting point: their fluidity gradually increases with increasing temperature. Amorphous substances include compounds such as wax, paraffin, most plastics, glass, etc.

However, crystalline substances have a specific melting point, i.e. a substance with a crystalline structure passes from a solid to a liquid state not gradually, but abruptly, upon reaching a specific temperature. Examples of crystalline substances include table salt, sugar, and ice.

The difference in the physical properties of amorphous and crystalline solids is primarily due to the structural features of such substances. What is the difference between a substance in an amorphous and a crystalline state can be most easily understood from the following illustration:

As you can see, in an amorphous substance, unlike a crystalline one, there is no order in the arrangement of particles. If in a crystalline substance you mentally connect two atoms close to each other with a straight line, you can find that the same particles will lie on this line at strictly defined intervals:

Thus, in the case of crystalline substances, we can talk about such a concept as a crystal lattice.

Crystal lattice called a spatial framework connecting the points of space in which the particles that form the crystal are located.

The points in space at which the particles forming the crystal are located are called crystal lattice nodes .

Depending on which particles are located at the nodes of the crystal lattice, they are distinguished: molecular, atomic, ionic And metal crystal lattices .

In nodes molecular crystal lattice

There are molecules within which the atoms are connected by strong covalent bonds, but the molecules themselves are held near each other by weak intermolecular forces. Due to such weak intermolecular interactions, crystals with a molecular lattice are fragile. Such substances differ from substances with other types of structure by significantly lower melting and boiling points, do not conduct electric current, and may or may not dissolve in various solvents. Solutions of such compounds may or may not conduct electric current, depending on the class of the compound. Compounds with a molecular crystal lattice include many simple substances - non-metals (hardened H 2, O 2, Cl 2, orthorhombic sulfur S 8, white phosphorus P 4), as well as many complex substances - hydrogen compounds of non-metals, acids, non-metal oxides, most organic substances. It should be noted that if a substance is in a gaseous or liquid state, it is inappropriate to talk about a molecular crystal lattice: it is more correct to use the term molecular type of structure.

In nodes atomic crystal lattice

there are atoms. Moreover, all the nodes of such a crystal lattice are “linked” together through strong covalent bonds into a single crystal. In fact, such a crystal is one giant molecule. Due to their structural features, all substances with an atomic crystal lattice are solid, have high melting points, are chemically inactive, insoluble in either water or organic solvents, and their melts do not conduct electric current. It should be remembered that substances with an atomic type of structure include boron B, carbon C (diamond and graphite), silicon Si from simple substances, and silicon dioxide SiO 2 (quartz), silicon carbide SiC, boron nitride BN from complex substances.

For substances with ionic crystal lattice

lattice sites contain ions connected to each other through ionic bonds.
Since ionic bonds are quite strong, substances with an ionic lattice have relatively high hardness and refractoriness. Most often, they are soluble in water, and their solutions, like melts, conduct electric current.
Substances with an ionic crystal lattice include metal and ammonium salts (NH 4 +), bases, and metal oxides. A sure sign of the ionic structure of a substance is the presence in its composition of both atoms of a typical metal and a non-metal.

observed in crystals of free metals, for example, sodium Na, iron Fe, magnesium Mg, etc. In the case of a metal crystal lattice, its nodes contain cations and metal atoms, between which electrons move. In this case, moving electrons periodically attach to cations, thus neutralizing their charge, and individual neutral metal atoms in return “release” some of their electrons, turning, in turn, into cations. In fact, “free” electrons do not belong to individual atoms, but to the entire crystal.

Such structural features lead to the fact that metals conduct heat and electric current well and often have high ductility (malleability).
The spread of melting temperatures of metals is very large. For example, the melting point of mercury is approximately minus 39 ° C (liquid under normal conditions), and tungsten is 3422 ° C. It should be noted that under normal conditions all metals except mercury are solids.

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Lesson type: Combined.

Objective of the lesson: To create conditions for the development of students’ ability to establish the cause-and-effect dependence of the physical properties of substances on the type of chemical bond and the type of crystal lattice, to predict the type of crystal lattice based on the physical properties of the substance.

Lesson objectives:

• To form concepts about the crystalline and amorphous state of solids, to familiarize students with various types of crystal lattices, to establish the dependence of the physical properties of a crystal on the nature of the chemical bond in the crystal and the type of crystal lattice, to give students basic ideas about the influence of the nature of chemical bonds and types of crystal lattices on the properties of matter .
• Continue to form the worldview of students, consider the mutual influence of the components of whole-structural particles of substances, as a result of which new properties appear, develop the ability to organize their educational work, and observe the rules of working in a team.
• To develop the cognitive interest of schoolchildren using problem situations;

Equipment: Periodic system D.I. Mendeleev, collection “Metals”, non-metals: sulfur, graphite, red phosphorus, crystalline silicon, iodine; Presentation “Types of crystal lattices”, models of crystal lattices of different types (table salt, diamond and graphite, carbon dioxide and iodine, metals), samples of plastics and products made from them, glass, plasticine, computer, projector.

Lesson progress

1. Organizational moment.

The teacher greets students and records those who are absent.

2. Testing knowledge on the topics “Chemical bonding.” Oxidation state.”

Independent work (15 minutes)

3. Studying new material.

The teacher announces the topic of the lesson and the purpose of the lesson. (Slide 1,2)

Students write down the date and topic of the lesson in their notebooks.

Updating knowledge.

The teacher asks questions to the class:

1. What types of particles do you know? Do ions, atoms and molecules have charges?
2. What types of chemical bonds do you know?
3. What aggregative states of substances do you know?

Teacher:“Any substance can be a gas, a liquid or a solid. For example, water. Under normal conditions it is a liquid, but it can be steam and ice. Or oxygen under normal conditions is a gas; at a temperature of -1940 C it turns into a blue liquid, and at a temperature of -218.8 ° C it solidifies into a snow-like mass consisting of blue crystals. In this lesson we will look at the solid state of substances: amorphous and crystalline.” (Slide 3)

Teacher: amorphous substances do not have a clear melting point - when heated, they gradually soften and turn into a fluid state. Amorphous substances include, for example, chocolate, which melts in both hands and mouth; chewing gum, plasticine, wax, plastics (examples of such substances are shown). (Slide 7)

Crystalline substances have a clear melting point and, most importantly, are characterized by the correct arrangement of particles at strictly defined points in space. (Slides 5,6) When these points are connected with straight lines, a spatial framework is formed, called a crystal lattice. The points at which crystal particles are located are called lattice nodes.

Students write down the definition in their notebooks: “A crystal lattice is a collection of points in space in which the particles that form a crystal are located. The points at which crystal particles are located are called lattice nodes.”

Depending on what types of particles are located at the nodes of this lattice, there are 4 types of lattices. (Slide 8) If there are ions at the nodes of a crystal lattice, then such a lattice is called ionic.

The teacher asks students questions:

– What will be the name of crystal lattices, in the nodes of which there are atoms and molecules?

But there are crystal lattices, at the nodes of which there are both atoms and ions. Such gratings are called metal gratings.

Now we will fill out the table: “Crystal lattices, type of bond and properties of substances.” As we fill out the table, we will establish the relationship between the type of lattice, the type of connection between particles and the physical properties of solids.

Let's consider the 1st type of crystal lattice, which is called ionic. (Slide 9)

– What is the chemical bond in these substances?

Look at the ionic crystal lattice (a model of such a lattice is shown). Its nodes contain positively and negatively charged ions. For example, a sodium chloride crystal is made up of positive sodium ions and negative chloride ions, forming a cube-shaped lattice. Substances with ionic crystal lattice include salts, oxides and hydroxides of typical metals. Substances with an ionic crystal lattice have high hardness and strength, they are refractory and non-volatile.

Teacher: The physical properties of substances with an atomic crystal lattice are the same as those of substances with an ionic crystal lattice, but often to a superlative degree - very hard, very durable. Diamond, which has an atomic crystal lattice, is the hardest substance of all natural substances. It serves as a standard of hardness, which according to a 10-point system is rated with the highest score of 10. (Slide 10). For this type of crystal lattice, you yourself will enter the necessary information into the table by working with the textbook yourself.

Teacher: Let's consider the 3rd type of crystal lattice, which is called metallic. (Slides 11,12) At the nodes of such a lattice there are atoms and ions, between which electrons move freely, connecting them into a single whole.

This internal structure of metals determines their characteristic physical properties.

Teacher: What physical properties of metals do you know? (malleability, plasticity, electrical and thermal conductivity, metallic luster).

Teacher: What groups are all substances divided into according to their structure? (Slide 12)

Let's consider the type of crystal lattice possessed by such well-known substances as water, carbon dioxide, oxygen, nitrogen and others. It's called molecular. (Slide14)

– What particles are located at the nodes of this lattice?

The chemical bond in molecules that are located at lattice sites can be either polar covalent or nonpolar covalent. Despite the fact that the atoms inside the molecule are connected by very strong covalent bonds, weak intermolecular forces of attraction act between the molecules themselves. Therefore, substances with a molecular crystal lattice have low hardness, low melting points and are volatile. When gaseous or liquid substances turn into solids under special conditions, then they develop a molecular crystal lattice. Examples of such substances can be solid water - ice, solid carbon dioxide - dry ice. This lattice has naphthalene, which is used to protect woolen products from moths.

– What properties of the molecular crystal lattice determine the use of naphthalene? (volatility). As we see, not only solids can have a molecular crystal lattice. simple substances: noble gases, H 2, O 2, N 2, I 2, O 3, white phosphorus P 4, but and complex: solid water, solid hydrogen chloride and hydrogen sulfide. Most solid organic compounds have molecular crystal lattices (naphthalene, glucose, sugar).

The lattice sites contain nonpolar or polar molecules. Despite the fact that the atoms inside the molecules are connected by strong covalent bonds, weak intermolecular forces act between the molecules themselves.

Conclusion: The substances are fragile, have low hardness, low melting point, and are volatile.

Question: Which process is called sublimation or sublimation?

Answer: The transition of a substance from a solid state of aggregation directly to a gaseous state, bypassing the liquid state, is called sublimation or sublimation.

Demonstration of experiment: sublimation of iodine

Then students take turns naming the information they wrote down in the table.

Crystal lattices, type of bond and properties of substances.

Teacher: What conclusion can we draw from the work done on the table?

Conclusion 1: The physical properties of substances depend on the type of crystal lattice. Composition of the substance → Type of chemical bond → Type of crystal lattice → Properties of substances . (Slide 18).

Question: Which type of crystal lattice from those discussed above is not found in simple substances?

Answer: Ionic crystal lattices.

Question: What crystal lattices are characteristic of simple substances?

Answer: For simple substances - metals - a metal crystal lattice; for non-metals – atomic or molecular.

Working with the Periodic System D.I. Mendeleev.

Question: Where are the metal elements located in the Periodic Table and why? Non-metal elements and why?

Answer : If you draw a diagonal from boron to astatine, then in the lower left corner of this diagonal there will be metal elements, because at the last energy level they contain from one to three electrons. These are elements I A, II A, III A (except boron), as well as tin and lead, antimony and all elements of secondary subgroups.

Non-metal elements are located in the upper right corner of this diagonal, because at the last energy level contain from four to eight electrons. These are the elements IV A, V A, VI A, VII A, VIII A and boron.

Teacher: Let's find non-metal elements whose simple substances have an atomic crystal lattice (Answer: C, B, Si) and molecular ( Answer: N, S, O , halogens and noble gases )

Teacher: Formulate a conclusion on how you can determine the type of crystal lattice of a simple substance depending on the position of the elements in D.I. Mendeleev’s Periodic Table.

Answer: For metal elements that are in I A, II A, IIIA (except boron), as well as tin and lead, and all elements of secondary subgroups in a simple substance, the type of lattice is metal.

For non-metal elements IV A and boron in a simple substance, the crystal lattice is atomic; and the elements V A, VI A, VII A, VIII A in simple substances have a molecular crystal lattice.

We continue to work with the completed table.

Teacher: Look carefully at the table. What pattern can be observed?

We listen carefully to the students’ answers, and then together with the class we draw a conclusion. Conclusion 2 (slide 17)

4. Fixing the material.

Test (self-control):

Substances that have a molecular crystal lattice, as a rule:
a) Refractory and highly soluble in water
b) Fusible and volatile
c) Solid and electrically conductive
d) Thermally conductive and plastic

The concept of “molecule” is not applicable to the structural unit of a substance:
a) Water
b) Oxygen
c) Diamond
d) Ozone

The atomic crystal lattice is characteristic of:
a) Aluminum and graphite
b) Sulfur and iodine
c) Silicon oxide and sodium chloride
d) Diamond and boron

If a substance is highly soluble in water, has a high melting point, and is electrically conductive, then its crystal lattice is:
a) Molecular
b) Nuclear
c) Ionic
d) Metal

5. Reflection.

6. Homework.

Characterize each type of crystal lattice according to the plan: What is in the nodes of the crystal lattice, structural unit → Type of chemical bond between the particles of the node → Interaction forces between the particles of the crystal → Physical properties due to the crystal lattice → Aggregate state of the substance under normal conditions → Examples.

Using the formulas of the given substances: SiC, CS 2, NaBr, C 2 H 2 - determine the type of crystal lattice (ionic, molecular) of each compound and, based on this, describe the expected physical properties of each of the four substances.

Instructions

As you can easily guess from the name itself, the metal type of lattice is found in metals. These substances are usually characterized by a high melting point, metallic luster, hardness, and are good conductors of electric current. Remember that lattice sites of this type contain either neutral atoms or positively charged ions. In the spaces between the nodes there are electrons, the migration of which ensures the high electrical conductivity of such substances.

Ionic type of crystal lattice. It should be remembered that it is also inherent in salts. Characteristic - crystals of the well-known table salt, sodium chloride. Positively and negatively charged ions alternate alternately at the sites of such lattices. Such substances are usually refractory and have low volatility. As you might guess, they are of the ionic type.

The atomic type of crystal lattice is inherent in simple substances - nonmetals, which under normal conditions are solids. For example, sulfur, phosphorus,... At the sites of such lattices there are neutral atoms connected to each other by covalent chemical bonds. Such substances are characterized by refractoriness and insolubility in water. Some (for example, carbon in the form) have exceptionally high hardness.

Finally, the last type of lattice is molecular. It is found in substances that are under normal conditions in liquid or gaseous form. As again can be easily understood from, at the nodes of such lattices there are molecules. They can be either non-polar (for simple gases such as Cl2, O2) or polar (the most famous example is water H2O). Substances with this type of lattice do not conduct current, are volatile, and have low melting points.

Sources:

• grating type

Temperature melting of a solid is measured to determine its purity. Impurities in a pure substance usually lower the temperature melting or increase the interval over which the compound melts. The capillary method is a classic method for controlling impurities.

You will need

• - test substance;
• - glass capillary, sealed at one end (diameter 1 mm);
• - glass tube with a diameter of 6-8 mm and a length of at least 50 cm;
• - heated block.

Instructions

Place the glass tube vertically on a hard surface and drop the capillary through it several times, sealed end down. This helps compact the substance. To determine the temperature, the column of the substance in the capillary should be about 2-5 mm.

Place the capillary thermometer in the heated block and observe the changes in the test substance as the temperature increases. Before and during heating, the thermometer should not touch the walls of the block or other highly heated surfaces, otherwise it may burst.

Note the temperature at which the first drops appear in the capillary (beginning melting), and the temperature at which the last substances disappear (end melting). In this interval, the substance begins to decrease until it completely transforms into a liquid state. When performing the analysis, also look for changes or decomposition of the substance.

Repeat measurements 1-2 more times. Present the results of each measurement in the form of the corresponding temperature interval during which the substance passes from solid to liquid. At the end of the analysis, make a conclusion about the purity of the test substance.

Video on the topic

In crystals, chemical particles (molecules, atoms and ions) are arranged in a certain order; under certain conditions they form regular symmetrical polyhedra. There are four types of crystal lattices - ionic, atomic, molecular and metallic.

Crystals

The crystalline state is characterized by the presence of long-range order in the arrangement of particles, as well as the symmetry of the crystal lattice. Solid crystals are three-dimensional formations in which the same structural element is repeated in all directions.

The correct shape of crystals is determined by their internal structure. If you replace molecules, atoms and ions in them with points instead of the centers of gravity of these particles, you get a three-dimensional regular distribution - . The repeating elements of its structure are called elementary cells, and the points are called nodes of the crystal lattice. There are several types of crystals depending on the particles that form them, as well as the nature of the chemical bond between them.

Ionic crystal lattices

Ionic crystals form anions and cations, between which there are. This type of crystal includes salts of most metals. Each cation is attracted to the anion and repelled by other cations, so it is impossible to isolate single molecules in an ionic crystal. The crystal can be considered as one huge one, and its size is not limited; it is capable of attaching new ions.

Atomic crystal lattices

In atomic crystals, individual atoms are united by covalent bonds. Like ionic crystals, they can also be thought of as huge molecules. At the same time, atomic crystals are very hard and durable, and do not conduct electricity and heat well. They are practically insoluble and are characterized by low reactivity. Substances with atomic lattices melt at very high temperatures.

Molecular crystals

Molecular crystal lattices are formed from molecules whose atoms are united by covalent bonds. Because of this, weak molecular forces act between molecules. Such crystals are characterized by low hardness, low melting point and high fluidity. The substances that they form, as well as their melts and solutions, do not conduct electric current well.

Metal crystal lattices

In metal crystal lattices, atoms are arranged with maximum density, their bonds are delocalized, and they extend throughout the entire crystal. Such crystals are opaque, have a metallic luster, are easily deformed, and are good conductors of electricity and heat.

This classification describes only limiting cases; most crystals of inorganic substances belong to intermediate types - molecular-covalent, covalent, etc. An example is a graphite crystal, inside each layer it has covalent-metallic bonds, and between the layers there are molecular ones.

Sources:

• alhimik.ru, Solids

Diamond is a mineral that belongs to one of the allotropic modifications of carbon. Its distinctive feature is its high hardness, which rightfully earns it the title of the hardest substance. Diamond is a fairly rare mineral, but at the same time it is the most widespread. Its exceptional hardness finds its application in mechanical engineering and industry.

Instructions

Diamond has an atomic crystal lattice. The carbon atoms that form the basis of the molecule are arranged in the form of a tetrahedron, which is why diamond has such high strength. All atoms are connected by strong covalent bonds, which are formed based on the electronic structure of the molecule.

The carbon atom has sp3 hybridized orbitals that are at an angle of 109 degrees and 28 minutes. The overlap of hybrid orbitals occurs in a straight line in the horizontal plane.

Thus, when the orbitals overlap at such an angle, a centered one is formed, which belongs to the cubic system, so we can say that diamond has a cubic structure. This structure is considered one of the strongest in nature. All tetrahedra form a three-dimensional network of layers of six-membered rings of atoms. Such a stable network of covalent bonds and their three-dimensional distribution leads to additional strength of the crystal lattice.