having various oxidation numbers Outer electron configurations:ns2npl~5 Example:The oxidation numbers of chlorine are+1,+3,+5,+7,-1,0。 Inert electron pair effect(惰性电子对效应)： The compounds of ELEMENTS of low oxidation number are more stable than those of high oxidation number when descending in the same groups 同族元素从上到下，低氧化值化合物比高氧化值化合物变得更稳定
Outer electron configurations：ns 2np 1 ~ 5 Example：The oxidation numbers of chlorine are +1，+3，+5，+7，-1，0。 Inert electron pair effect (惰性电子对效应)： ◆ having various oxidation numbers The compounds of ELEMENTS of low oxidation number are more stable than those of high oxidation number when descending in the same groups 同族元素从上到下，低氧化值化合物比高氧化值化合物变得更稳定
Example: Si(ID)<Si(IV)in light of stability electron configurations are [Ne]3s2 for Si(II)and [Ne]for Si(IV),respectively. Pb(II)>Pb(IV))in light of stability electron configurations are Xe]6s2 (inert electron pair effect for Pb(II)and [Xe]for Pb(IV),respectively Large electronegativity,forming covalent compounds
Example： Si(II) < Si(IV) in light of stability electron configurations are [Ne]3s2 for Si(II) and [Ne] for Si(IV), respectively. Pb(II) > Pb(IV) ) in light of stability electron configurations are [Xe]6s2 (Inert electron pair effect ) for Pb(II) and [Xe] for Pb(IV), respectively. ◆ Large electronegativity, forming covalent compounds
13.2 The elements of boron family 13.2.1 Outline on boron family >13.2.2 The elemental substances of boron family 13.2.3 The compounds of boron -*13.2.4 The compounds of aluminum
§ 13.2 The elements of boron family *13.2.4 The compounds of aluminum 13.2.3 The compounds of boron 13.2.2 The elemental substances of boron family 13.2.1 Outline on boron family
13.2.1 Outline on boron family Boron family (IA):B,Al,Ga,In,TI Valence electron configuration:ns2npl Electron deficient elements:number of valence electrons number of valence orbits Electron deficient compounds:number of electron pairs in bonding molecular orbits number of valence orbits(即：还有空的成键轨道) Example:BF3(sp3),H3BO3.B:2S22pl HBF is not electron deficient compound
13.2.1 Outline on boron family Boron family (ⅢA)：B，Al，Ga，In，Tl Valence electron configuration：ns 2np 1 Electron deficient elements: number of valence electrons < number of valence orbits Electron deficient compounds: number of electron pairs in bonding molecular orbits < number of valence orbits(即：还有空的成键轨道). Example：BF3 (sp3 ), H3BO3。 B: 2S22p1 HBF4 is not electron deficient compound
2p 2P excited 2s $p2 B:2s22p1 sp2 hybridization The formation of BF
of BF3 The formation 2s 2p 2p 2s sp 2 sp2 hybridization B ： 2s 22p 1 excited