听力原文:M: Would it be better to buy a monthly meal ticket or pay for each meal separately? W: What difference does it make? The price per meal is the same either way. Q: What does the woman imply? (18)
【简答题】(14分) A、B、C、D、E是位于短周期的主族元素。已知:①热稳定性:H m D>H m C;② 、 具有相同的电子层结构;③A与B在同一周期,在该周期所有主族元素中,A的原子半径最大,B的离子半径最小;④A与B质子数之和是D质子数的3倍。依据上述信息用相应的化学用语回答下列问题: (1) H m D m 的电子式___________________。 (2) 、 的还原性强弱顺序为:...