A, chemical bonds:

1, which means: strong interaction between adjacent atoms (or ions) in a molecule or crystal.

2. Types, namely ionic bond, * * valence bond and metal bond.

Ionic bonds are attractive forces generated by opposite charges, for example, chlorine and sodium combine into NaCl through ionic bonds.

1, combining the electrostatic action of anions and cations.

2. Binding particles: anions and cations

3. Forming ionic bonds: active metals and active nonmetals.

Part b salt (Nacl, NH4cl, BaCo3, etc. )

Strong alkali (sodium hydroxide, potassium hydroxide)

D. Active metal oxides and peroxides

4. It is proved that ionic compounds can conduct electricity in molten state.

* * * Valence bond is the absolute value of valence of two or more atoms passing through * * * electrons (1, * * * electron logarithm = element.

2. The compound with * * * valence bond is not necessarily a * * * valence compound)

A typical valence bond is formed by two atoms attracting a pair of bonding electrons. For example, two hydrogen nuclei attract a pair of electrons at the same time to form a stable hydrogen molecule.

Electronic representation of 1, * * valence molecule, P 13.

Expression of structural formula of 2, * * * valence molecule

3. * * * Valence molecular rod model (H2O-discount model, NH3-triangular cone, CH4-regular tetrahedron)

4, * * valence molecular proportion model

Supplement: Carbon atoms are usually combined with other atoms through valence bonds.

Ethane (carbon-carbon single bond)

Ethylene (carbon-carbon double bond)

Acetylene (carbon-carbon triple bond)

Metal bond is an interaction that binds metal atoms together, which can be regarded as a highly delocalized valence bond.

Second, intermolecular force (i.e. van der Waals force)

1, features: A exists in compounds with valence of * * *

Chemical bonds are much weaker.

C affects the melting point and solubility-for molecules with similar composition and structure, van der Waals force generally increases with the increase of relative molecular mass. Instantaneous boiling point will also rise (special cases: HF, NH3, H2O).

Third, hydrogen bonding.

1, with elements: O(H2O), N(NH3) and F(HF).

2. Features: stronger than van der Waals force and weaker than chemical bond.

Supplement: Hydrogen bonds exist in any state of water.