Diagram of the formation of an ionic bond between magnesium and fluorine. Schemes of the formation of substances with different types of bonds. Examples of ionic bond formation

Ionic chemical bond is the bond that forms between atoms chemical elements(positively or negatively charged ions). So what is ionic bond and how is it formed?

General characteristics of the ionic chemical bond

Ions are charged particles that atoms become when they donate or accept electrons. They are attracted to each other quite strongly, it is for this reason that substances with this type of bond have high boiling and melting points.

Rice. 1. Ions.

An ionic bond is a chemical bond between dissimilar ions due to their electrostatic attraction. It can be considered the limiting case of a covalent bond, when the difference between the electronegativity of the bound atoms is so great that complete separation of charges occurs.

Rice. 2. Ionic chemical bond.

It is usually believed that the bond acquires an electronic character if EC > 1.7.

The difference in the value of electronegativity is greater, the further the elements are located from each other in the periodic system by period. This connection is characteristic of metals and non-metals, especially those located in the most remote groups, for example, I and VII.

Example: table salt, sodium chloride NaCl:

Rice. 3. Scheme of the ionic chemical bond of sodium chloride.

The ionic bond exists in crystals, it has strength, length, but is not saturated and not directed. Ionic bonding is characteristic only for complex substances, such as salts, alkalis, and some metal oxides. In the gaseous state, such substances exist in the form of ionic molecules.

An ionic chemical bond is formed between typical metals and non-metals. Electrons without fail pass from the metal to the non-metal, forming ions. As a result, an electrostatic attraction is formed, which is called an ionic bond.

In fact, a completely ionic bond does not occur. The so-called ionic bond is partly ionic, partly covalent. However, the bond of complex molecular ions can be considered ionic.

Examples of ionic bond formation

There are several examples of the formation of an ionic bond:

interaction of calcium and fluorine

Ca 0 (atom) -2e \u003d Ca 2 + (ion)

It is easier for calcium to donate two electrons than to receive the missing ones.

F 0 (atom) + 1e \u003d F- (ion)

- Fluorine, on the contrary, is easier to accept one electron than to give seven electrons.

Let us find the least common multiple between the charges of the formed ions. It is equal to 2. Let's determine the number of fluorine atoms that will accept two electrons from a calcium atom: 2: 1 = 2. 4.

Let's make a formula for an ionic chemical bond:

Ca 0 +2F 0 →Ca 2 +F−2.

interaction of sodium and oxygen

4.3. Total ratings received: 313.

This lesson is devoted to the generalization and systematization of knowledge about the types of chemical bonds. During the lesson, schemes for the formation of a chemical bond in various substances. The lesson will help to consolidate the ability to determine the type of chemical bond in a substance by its chemical formula.

Topic: Chemical bond. Electrolytic dissociation

Lesson: Schemes for the formation of substances with different types of bonds

Rice. 1. Scheme of bond formation in a fluorine molecule

The fluorine molecule consists of two atoms of the same non-metal chemical element with the same electronegativity, therefore, a covalent non-polar bond is realized in this substance. Let us depict the scheme of bond formation in a fluorine molecule. Rice. one.

Around each fluorine atom, using dots, we draw seven valence, that is, external, electrons. Before a steady state, each atom needs one more electron. Thus, one common electron pair is formed. Replacing it with a dash, we will depict the graphic formula of the fluorine molecule F-F.

Conclusion:a covalent non-polar bond is formed between the molecules of one chemical element-non-metal. With this type of chemical bond, common electron pairs are formed that equally belong to both atoms, that is, there is no shift in the electron density to any of the atoms of the chemical element

Rice. 2. Scheme of bond formation in a water molecule

The water molecule consists of hydrogen and oxygen atoms - two non-metal elements with different values of relative electronegativity, therefore, in this substance there is a covalent polar bond.

Since oxygen is a more electronegative element than hydrogen, shared electron pairs shift towards oxygen. A partial charge arises on the hydrogen atoms, and a partial negative charge on the oxygen atom. Replacing both common electron pairs with dashes, or rather arrows showing the shift in electron density, we write down the graphical formula for water Fig. 2.

Conclusion:a covalent polar bond occurs between atoms of different non-metal elements, that is, with different values of relative electronegativity. With this type of bond, common electron pairs are formed, which are shifted towards a more electronegative element..

1. No. 5,6,7 (p. 145) Rudzitis G.E. Inorganic and organic chemistry. Grade 8: textbook for educational institutions: a basic level of/ G. E. Rudzitis, F.G. Feldman. M.: Enlightenment. 2011 176 pp.: ill.

2. Indicate the particle with the largest and smallest radius: Ar atom, ions: K +, Ca 2+, Cl -. Justify your answer.

3. Name three cations and two anions that have the same electron shell as the F - ion.

Help is on the way, hold on.
a) Consider the formation of an ionic bond between sodium and
oxygen.
1. Sodium - an element of the main subgroup of group I, a metal. It is easier for its atom to give the I outer electron than to accept the missing 7:

1. Oxygen is an element of the main subgroup of group VI, non-metal.
It is easier for its atom to accept 2 electrons, which are not enough to complete the outer level, than to give 6 electrons from the outer level.

1. First, we find the least common multiple between the charges of the formed ions, it is equal to 2(2∙1). In order for Na atoms to give up 2 electrons, they must be taken 2 (2: 1), in order for oxygen atoms to be able to accept 2 electrons, they must be taken 1.
2. Schematically, the formation of an ionic bond between sodium and oxygen atoms can be written as follows:

b) Consider the scheme for the formation of an ionic bond between lithium and phosphorus atoms.
I. Lithium - an element of group I of the main subgroup, a metal. It is easier for its atom to donate 1 outer electron than to accept the missing 7:

2. Chlorine - an element of the main subgroup of group VII, non-metal. His
It is easier for an atom to accept 1 electron than to donate 7 electrons:

2. Least common multiple of 1, i.e. in order for 1 atom of lithium to give away, and a chlorine atom to accept 1 electron, you need to take them one at a time.
3. Schematically, the formation of an ionic bond between lithium and chlorine atoms can be written as follows:

c) Consider the scheme for the formation of an ionic bond between atoms
magnesium and fluorine.
1. Magnesium is an element of group II of the main subgroup, a metal. His
it is easier for an atom to donate 2 outer electrons than to accept the missing 6:

2. Fluorine - an element of the main subgroup of group VII, non-metal. His
it is easier for an atom to accept 1 electron, which is not enough to complete the outer level, than to give 7 electrons:

2. Find the least common multiple between the charges of the formed ions, it is equal to 2(2∙1). For magnesium atoms to donate 2 electrons, only one atom is needed, so that fluorine atoms can accept 2 electrons, they need to be taken 2 (2: 1).
3. Schematically, the formation of an ionic bond between lithium and phosphorus atoms can be written as follows:

This lesson is devoted to the generalization and systematization of knowledge about the types of chemical bonds. During the lesson, schemes for the formation of chemical bonds in various substances will be considered. The lesson will help to consolidate the ability to determine the type of chemical bond in a substance by its chemical formula.