General properties of boron family elements Except for B which is a metalloid(非金属)，Al, Ga,In,Tl are all metals. Oxidation numbers:B,Al,Ga:(+3) In:(+1,+3) T:(+1) Maximum coordination numbers: B:4 example:HBF4(sp3杂化) others:6 example:Na3AlF6(sp3d2杂化)General properties of boron family elements • Except for B which is a metalloid(非金属), Al， Ga，In，Tl are all metals. • Oxidation numbers：B，Al，Ga：(+3) In：(+1，+3) Tl：(+1) • Maximum coordination numbers： B：4 example：HBF4 (sp3杂化) others：6 example：Na3AlF6 (sp3d 2杂化)