题目

When I was six, Dad brought home a dog one day, who was called “Brownie”, My brothers and I all loved Brownie and did different things with her. One of us would walk her, another would feed her ,then there were baths, playing catch and many other games .Brownie, in return, loved each and every one of us. One thing that most touched my heart was that she would go to whoever was sick and just be with them. We always felt better when she was around. One days, as I was getting her food, she chewed up(咬破) one of Dad’s shoes, which had to be thrown away in the end. I knew Dad would be mad 已知：在热力学标准态（298K、1.01×105Pa）下，由稳定的单质发生反应生成1mol化合物的反应热叫该化合物的生成热（△H）．下图为氧族元素氢化物a、b、c、d的生成热数据示意图．试回答下列问题：（1）写出氧族元素中含有18e-的两种氢化物的电子式．（2）请你归纳：非金属元素氢化物的稳定性与氢化物的生成热△H的关系非金属元素氢化物越稳定，△H越小，反之亦然非金属元素氢化物越稳定，△H越小，反之亦然（3）写出硫化氢在热力学标准态下，发生分解反应的热化学反应方程式：H2S（g）=S（s）+H2（g）；△H=+20kJ/molH2S（g）=S（s）+H2（g）；△H=+20kJ/mol．