1、The character of Group A elements Group 1A Elements (ns1, n 2) Group 2A Elements (ns2, n 2) Group 3A Elements (ns2np1, n 2) Group 4A Elements (ns2np2, n 2) Group 5A Elements (ns2np3, n 2) Group 6A Elements (ns2np4, n 2) Group 7A Elements (ns2np5, n 2) Group 8A Elements (ns2np6, n 2)3Group 1A Element
2、s (ns1, n 2)M M+1 + 1e-2M(s) + 2H2O(l) 2MOH(aq) + H2(g)4M(s) + O2(g) 2M2O(s)Increasing reactivity4Group 1A Elements (ns1, n 2)5Group 2A Elements (ns2, n 2)M M+2 + 2e-Be(s) + 2H2O(l) No ReactionIncreasing reactivityMg(s) + 2H2O(g) Mg(OH)2(aq) + H2(g)M(s) + 2H2O(l) M(OH)2(aq) + H2(g) M = Ca, Sr, or Ba
3、6Group 2A Elements (ns2, n 2)7Group 3A Elements (ns2np1, n 2)4Al(s) + 3O2(g) 2Al2O3(s)2Al(s) + 6H+(aq) 2Al3+(aq) + 3H2(g)8Group 3A Elements (ns2np1, n 2)9Group 4A Elements (ns2np2, n 2)Sn(s) + 2H+(aq) Sn2+(aq) + H2 (g)Pb(s) + 2H+(aq) Pb2+(aq) + H2 (g)10Group 4A Elements (ns2np2, n 2)11Group 5A Eleme
4、nts (ns2np3, n 2)N2O5(s) + H2O(l) 2HNO3(aq)P4O10(s) + 6H2O(l) 4H3PO4(aq)12Group 5A Elements (ns2np3, n 2)13Group 6A Elements (ns2np4, n 2)SO3(g) + H2O(l) H2SO4(aq)14Group 6A Elements (ns2np4, n 2)15Group 7A Elements (ns2np5, n 2)X + 1e- X-1X2(g) + H2(g) 2HX(g)Increasing reactivity16Group 7A Elements
5、 (ns2np5, n 2)17Group 8A Elements (ns2np6, n 2)Completely filled ns and np subshells.Highest ionization energy of all elements.No tendency to accept extra electrons.18Compounds of the Noble GasesA number of xenon compounds XeF4, XeO3, XeO4, XeOF4 exist.A few krypton compounds (KrF2, for example) hav
6、e been prepared.19The metals in these two groups have similar outer electron configurations, with one electron in the outermost s orbital.Chemical properties are quite different due to difference in the ionization energy.Comparison of Group 1A and 1BLower I1, more reactive20Properties of Oxides Across a Periodbasic acidicPeriodic Table of Electronegativities
