Drawing the electro shell diagram and valence structure

oxygen molecule --- double covalent bond 双键

nitrogen molecule--- triple covalent bond 三键

Notice:

when we drawing the electro shell digram, one pair of electron has two electrons( dot )

formed one solid line (covalent bond).

在化共价键的时候，两个电子为一对，单键 共享2个电子，双键共享4各电子，三键

共享6个电子，形成最外层电子为8的饱和状态。

Covalent compound--- key concept

• By sharing electron within the molecule （nothing with gain or lose electrons )

• Bonding pair : pair of electrons shared between two atoms that is involved in forming a

covalent bond

• Lone pair (non bonding pair): electron pair around an atom in molecule that is not shared by

any other atoms; although not involved in bonding, non-bonding pair around any central

atom influence the shape of the molecule.

• Shape of the molecule