What are covalent compounds called? What is a shared electron pair?

A covalent compound is a compound that binds with a common electron pair.

A shared electron pair is when two atoms each donate an electron, forming an atomic pair in the middle of two atoms.

1. Essential difference: those that cannot conduct electricity in the molten state are covalent compounds, and those that can conduct electricity are ionic compounds.

2. The difference in elemental composition: the compound containing ammonium must be ionic compounds, aluminum chloride is a covalent compound, and all compounds that do not contain metal elements and ammonium ions are covalent compounds.

Clause. 1. 2. The main group of metal elements and the first.

The compounds of the six and seven main group non-metallic elements are ionic compounds, and most of the salts formed between potassium, sodium, ammonium, calcium and magnesium salts, metal elements and acid ions (such as sulfuric acid and ion, nitric acid and carbonic acid ion) are ionic compounds (except for AlCl3, HgCl2, ZnCl2, BeCl2, etc.).

3. Differences in material categories: strong bases are ionic compounds, active metal peroxides are ionic compounds, active metal oxides, and compounds (CO2, CLO2, B2H6, BF3, NCL3, etc.) formed by the combination of atoms of different non-metallic elements are covalent compounds.

Molecules that are bound together by covalent bonds between atoms are called covalent molecules. Covalent molecules include elemental (e.g., O2) and compounds (e.g., H2O). Whereas, covalent compounds are just a part of the covalent molecule. The difference between the two is in all and in part.

The difference and relationship between covalent compounds and covalent molecules Ions are charged, as long as the electrical power (as long as there are positive and negative signs) is an ion, the molecule is a whole, ionic compounds are composed of anion and cation, containing ionic bonds, covalent compounds are composed of atoms, containing covalent bonds, and ionic compounds may also have covalent bonds.

1) Ionic compounds: Rock compounds composed of anionic and cationic phases are called ionic compounds.

2) Covalent compounds: Compounds in which atoms of different elements share electron pairs to form molecules are called covalent compounds.

1. Covalent compounds occur between non-metal atoms, while ionic compounds occur between typical non-metal atoms and typical metal atoms.

2. Covalent compounds form a stable structure by sharing electron pairs, which forms a whole, which is the molecule we have learned. Ionic compounds are accumulation of ions at room temperature and pressure, and there are no molecules individually. (Molecules are present only in the vapor state).

3. The molecules of covalent compounds have a small gravitational attraction to each other, so they are often easy to diffuse at room temperature and pressure to form gases, while ionic compounds are made up of many ions with different charges that attract each other with electrostatic gravity, and the gravitational force is large, so they often form solids at room temperature and pressure.

Diagram of covalent bonds in water: the structural formula is represented by **, and the electronic formula is represented by dots.

Covalent bonds differ from ionic bonds in that the atoms that enter the covalent bonds do not show an outward charge because they do not gain or lose electrons. Covalent bonds are stronger than hydrogen bonds and are not much worse than ionic bonds or sometimes even stronger than ionic bonds. The essence is the formation of shared electron pairs between atoms.

It is generally believed that when the electronegativity difference between the two elements is greater than that, it forms an ionic bond; When it is less than, it becomes a covalent bond.

Saturation. In the process of covalent bond formation, because the number of unpaired electrons that each protogenzi can provide is certain, one unpaired electron of an atom can not be paired with other electrons after being paired with the unpaired electrons of other atoms, that is, the total number of covalent bonds that can be formed by each atom is a certain state, which is the saturation of covalent bonds. The saturation of covalent bonds determines the number of atoms that bind to each other when forming molecules, which is one of the internal reasons for the law of definite proportion.

The above content reference: Encyclopedia - Covalent Bond.

Compounds that share electron pairs to form molecules are called covalent compounds.

Whether two atoms are bonded in the form of covalent bonds or ionic bonds mainly depends on the electronegativity difference of the two atoms. The combination of metals and non-metals with a large electronegativity difference is dominated by ionic bonds; The combination of two non-metals with a small electronegativity difference is dominated by covalent bonds.

A covalent bond is a chemical bond formed by the interaction of atoms of two elements with the same or little electronegativity by sharing electron pairs. Compounds formed by covalent bonds are called covalent compounds.

In order to elucidate this type of chemical bonding problem, as early as 1916, the American chemist Lewis proposed the theory of covalent bonds between atoms that share electron pairs. According to this theory, each atom in a molecule tries to achieve the electronic structure of the corresponding noble gas atom by sharing one or several pairs of electrons.

Valence bond theory is a generalization of quantum mechanics approximate processing of hydrogen molecules, also known as electron pairing method, abbreviated as VB method. This method differs from Lewis's covalent bond theory in that it is based on quantum mechanics. The basic points of valence bond theory are as follows:

1) When single electrons with opposite spins in an atom approach each other, the single electrons can pair up to form a stable chemical bond (single, double, or triple bond).

2) If there is no single electron in the atom or there is a single electron but the spin direction is the same, neither covalent bond can be formed. For example, the helium atom has 2 1s electrons, and it cannot form the HE2 molecule.

3) The more atomic orbitals overlap of bonding electrons, the greater the probability density between nuclei, the stronger the covalent bond formed, and the more stable the molecule, so it can be seen that the formation of covalent bonds will follow the direction of the maximum overlap of atomic orbitals within the possible range, which is the principle of maximum overlap of suborbitals.