What are hydrogen bonds, ionic bonds, and covalent bonds?

Hydrogen bonds, ionic bonds.

Covalent bonds are names given by people to distinguish the different interactions between particles. Ionic and covalent bonds belong to chemical bonds.

The melting and boiling point of substances formed by chemical bonds between particles is relatively high. Reactive metals and reactive nonmetals are easy to form ionic bonds, such as the Ia, IIA and VIA and VIIA elements generally form ionic bonds, and the ammonium ions in the ammonium salt are also ionic bonds between the acid ions. Covalent bonds are generally formed between non-metallic elements, such as HCl, SiO2, etc.

HCl is covalent bonds within the molecule, and intermolecular forces are intermolecular forces.

So the melting boiling point is low. SiO2 is all composed of covalent bonds and belongs to atomic crystals with a high melting and boiling point.

Hydrogen bonding does not belong to chemical bonds because it is much weaker than chemical bonds, water is a typical substance with hydrogen bonds, and it has a much lower melting point than NaCl (ionic bonds) and SiO2 (covalent bonds). Hydrogen bonding is an intermolecular force that is stronger than the general intermolecular force. The conditions for its formation are:

Hydrogen. The role of the formation of non-metallic elements, typical hydrogen-containing bonds are water, HF, NH3They respectively have a higher melting and boiling point than the hydrides of other elements of the same main group.

Hydrogen bonding is the force between the molecules of certain covalent compounds and is not a chemical bond. n, o, f, containing hydrogen.

An ionic bond is one of the forces that act between ions in an ionic compound, one of the chemical bonds.

A covalent bond is a force that acts between atoms in a covalent compound or non-metallic element. One of the chemical bonds.

A covalent bond is a chemical bond.

In a way where two or more atoms share their outer electrons to ideally reach a state of electron saturation and thus form a relatively stable chemical structure, such as a strong interaction between several adjacent atoms by sharing electrons and sharing electrons is called a covalent bond.

Ionic bond. Formed after becoming an ion by losing or gaining electrons from two or more atoms or chemical groups. There is electrostatic interaction between oppositely charged ions, and when two oppositely charged ions are in close proximity, they appear to attract each other, while electrons and electrons, nuclei.

There is also electrostatic repulsion between the nucleus and the nucleus, and when the electrostatic attraction and electrostatic repulsion reach equilibrium, ionic bonds are formed.

Essence:

Ionic bonds belong to chemical bonds, most of which are salts, made up of alkali metals or alkaline earth metals.

The bonds formed, the active metal oxides all have ionic bonds. Compounds that contain ionic bonds are called ionic compounds.

Ionic bonds are related to the melting boiling point and hardness of an object.

Its essence is that after the overlapping of atomic orbits, there is a high probability of electrons between two nuclei and the electrical interaction between two nuclei.

The above content refers to Encyclopedia - Covalent Bonds.

Encyclopedia - Ionic bonds.

What is the difference between covalent and ionic bonds.

It can be distinguished by the following three different points:

1. The formation process is different: ionic bonds.

It is the electrons that are gained and lost between atoms to form anions and cations.

Then the anion and cation are formed by electrostatic action, covalent bonds.

It is formed between atoms by sharing electron pairs, there is no gain or loss of electrons between atoms, and there are no anions and cations in the formed compounds.

2. Different directionality during bonding: ionic bonds have no directionality when bonding, while covalent bonds do. Ionic bonds are chemical bonds formed by electrostatic attraction between cations and cations.

An ion can equally attract oppositely charged ions in any direction, so the ionic bond is not directional.

Whereas covalent bonds are quite different, the formation of covalent bonds is an electron cloud of bonding atoms.

If the electron cloud overlaps and the more the electron cloud is defeated, the greater the density of the electron cloud between the two cores, and the stronger the covalent bond is formed.

3. Different properties: covalent bond is a kind of chemical bond, two or more atoms use outer electrons together, and ideally reach the state of electron saturation, and ionic bond is a kind of chemical bond, which is formed after two or more atoms lose or gain electrons and become ions. This type of chemistry tends to form between metals and non-metals.

Overlapping forms

The electron cloud theory reduces the formation of covalent bonds into overlapping forms, which are divided into the form of bonds and bonds.

The bond is an s orbital of two nuclei.

Approaching each other is similar to the form of heads meeting. The bond is a covalent bond formed in the way the p orbital shoulders touch the shoulders close together.

Bonds are more prone to breakage as compared to bonds, so it leads to ethylene (chch) and ethane.

ch ch) is not very consistent in nature.

The bond energy of hydrogen bond is less than that of covalent bond, greater than intermolecular force, and belongs to a kind of dispersion force in van der Waals force, which can be classified as intermolecular force, but it cannot be a covalent bond, because it is not really bonded, for example, water is generated by the electrostatic attraction of hydrogen and oxygen atoms of different molecules after the shift of lone pairs of electrons makes hydrogen atoms positive and oxygen atoms appear negative.

Physicochemical properties of hydrogen bonding:

Hydrogen bonds are usually formed when the substance is in a liquid state, but can sometimes continue to exist in some crystalline or even gaseous substances after they have been formed. For example, hydrogen bonds are present in HF in gaseous, liquid, and solid states. There are many substances that can form hydrogen bonds, such as water, hydrates, ammonia, inorganic acids, and certain organic compounds.

The presence of hydrogen bonds affects certain properties of matter.

When the substances with hydrogen bonds between the molecules are melted or gasified, in addition to overcoming the pure intermolecular forces, the temperature must also be increased to return early, and an additional amount of energy must be used to break the hydrogen bonds between molecules, so the melting and boiling points of these substances are higher than the melting and boiling points of the same series of hydrides.

Hydrogen bonds are formed within the molecule, and the melting and boiling points are often reduced. Because the melting point of a substance is related to the intermolecular forces, if hydrogen bonds are formed within the molecules, then the corresponding intermolecular forces will be reduced, and the intramolecular hydrogen bonds will reduce the melting and boiling point of the substance. For example, o-nitrophenol with intramolecular hydrogen bonds has a lower melting point (45) than those with intermolecular hydrogen bonds (96) and para-melting points (114).

In polar solvents, if hydrogen bonds can be formed between the solute molecules and the spike of the solvent molecules, the solubility of the solute increases. The solubility of HF and NH3 in water is relatively large, which is why it is for this reason. Liquids with hydrogen bonds between molecules are generally more viscous.

For example, polyhydrol compounds such as glycerin, phosphoric acid, and concentrated sulfuric acid are usually viscous liquids due to the numerous hydrogen bonds that can form between molecules.

1. Hydrofluoric acid: The hydrogen atom and other fluorine atoms produce a hydrogen bond, and the fluorine atom itself has only one lone pair of electrons, and can only produce one hydrogen bond, so there are two hydrogen bonds.

2. Water: Two hydrogen atoms and the oxygen atoms of another water molecule form two hydrogen bonds. At the same time, the oxygen atom of the water molecule has two pairs of lone pairs of electrons, which can form hydrogen bonds with the hydrogen atoms of other water molecules, so there are four hydrogen bonds.

The hydrogen atom is bonded to the electronegative atom x by a covalent bond, and if it is close to the atom y(o f n, etc.), which is highly electronegative and has a small semi-unbridled diameter, hydrogen is used as a medium between x and y to generate x-h....A special intermolecular or intramolecular interaction in the form of y.

1 The formation process of ionic bonds and covalent bonds is different Ionic bonds are formed by the gain and loss of electrons between atoms to form anions and cations, and then anions and cations are formed through electrostatic action; Covalent bonds are formed between atoms by sharing electron pairs, and there is no gain or loss of electrons between atoms, and there are no anion and cation in the formed compounds. 2 Ionic bonds and covalent bonds have different directionality in bonding Ionic bonds have no directionality in bonding, whereas covalent bonds are directional. We know that ionic bonds are chemical bonds formed between cations and cations by electrostatic attraction.

Since the charge gravitational distribution of cations and cations is spherically symmetrical, an ion can equally attract oppositely charged ions in any direction, so the ionic bonds are not directional. The covalent bond is very different, the formation of the covalent bond is the overlap of the electron cloud of the bonding atoms, if the degree of electron cloud overlap is more, the greater the density of the electron cloud between the two nuclei, the stronger the covalent bond will be, so the formation of the covalent bond will be carried out as far as possible along the direction of the maximum density of the electron cloud. Except for the electron clouds of the s orbitals, which are spherically symmetrical and have no directionality when they overlap each other, the electron clouds of the other p, d, and f orbitals all have a certain stretching direction in space, so they all have directionality when forming bonds.

The directionality of the covalent bond determines the spatial arrangement of the atoms in the molecule. Whether the atomic arrangement is symmetrical or not plays an important role in determining the polarity of the molecule. 3 Ionic bonds and covalent bonds have different saturation at the time of bond formation Ionic bonds do not have saturation, whereas covalent bonds do.

The fact that an ionic bond is not saturated means that an ion can attract more oppositely charged ions than its valency, but it does not mean that it attracts any number of ions. Actually, the number of oppositely charged ions attracted by an ion is certain due to the spatial effect. For example, in salt crystals, one Na+ attracts six Cl-s, while one Cl- attracts six Na+

It can also be said that the coordination number of Na+ and Cl- is six. The saturation of covalent bonds, which refers to the formation of covalent bonds by unpaired electrons in electrons. If there are several unpaired electrons in an atom, they can pair with several electrons that are opposite to each other in the direction of spin to form several covalent bonds.

After bonding, there are no more unpaired electrons, and no more bonds can be formed. We know that if the shared electron pair is in the middle of two atoms that are bonded, it is a non-polar bond; If the shared electron pair is slightly biased towards a certain atom, it is a weakly polar bond; If the shared electron pair is biased towards a certain atom, it is a strongly polar bond; When the shared electron pair is biased too strongly towards an atom, it even loses electrons and becomes an ionic bond. Therefore, it can be said that non-polar bonds and ionic bonds are the two extremes of covalent bonds, while polar bonds are intermediate states of transition from non-polar bonds to ionic bonds.

Therefore, there is no strict boundary between ionic, polar and non-polar bonds. That is to say, pure ionic bonds and pure covalent bonds are only a part, while most bonds are polar bonds with some degree of ionic and covalent properties. Only the covalent bonds between the same non-metal atoms have a covalent property of 100, and the bonds between different atoms have a certain ionic property.