12. Neither is right. When the first n=3, there is an s, three p's and five d 's.
The second first three quantum numbers describe orbital quantum numbers, and the fourth spin quantum number describes the spin direction of electrons.
13. 1) * * Valence bond, van der Waals force 2) * * Valence bond van der Waals force 3) * * Valence bond hydrogen bond van der Waals force ionic bond (considering the dissociation of water) 4) * * Valence bond hydrogen bond van der Waals force ionic bond (van der Waals force includes several kinds, orientation force (both are dipoles).
14. Generally speaking, the longer the bond length, the lower the bond energy, the lower the melting point and the lower the hardness.
Metal crystals consist of metal cations and free electrons. The interaction between metal cations and free electrons is called metal bond, and its strength determines the melting point, hardness and other physical properties of metals.
The valence bond is a kind of chemical bond. Two or more atoms * * * use their outer electrons to reach the state of electron saturation under ideal conditions, thus forming a relatively stable and solid chemical structure called * * * valence bond.
Ionic bonds are formed by electron transfer (cations lose electrons and anions gain electrons). That is, the chemical bond formed between positive ions and negative ions due to electrostatic attraction.
There are three basic types of chemical bonds, namely ionic bonds, valence bonds and metal bonds.
Valence refers to the ratio between one atom and other atoms that make up a compound. There are positive and negative valence.
A chemical bond is a way to combine atoms or groups of compounds. There are ionic bonds, valence bonds and metal bonds.
The combination mode of metal binder makes it more malleable.