solid elements,coded as g,j and q,belong to the same period of the periodic table,and form oxides with the following properties:
go3 reacts with water to form a strongly acidic solution,
j2o3 reacts with strong acids and strong alkalis,
q2o reacts with water to form a strongly alkaline solution.
(a)state which oxide would be described as amphoteric.(1 mark)
(b)state,giving reasons,which of g,j or q is most electronegative.(2 mark)
(c)state,giving reasons,which oxide is molecular.(3 mark)
解答：g为s(硫)，j为al(铝)，q为na(钠)。
（a）al2o3为两性氧化物，既可与强酸反应，又可与强碱反应。
（b）一般来说，周期表从左到右，元素的电负性逐渐变大，而从上到下，元素的电负性则逐渐变小，所以电负性最大的是硫元素，其次是铝，最小的是钠。
（c）常温下so3为气体，al2o3为固体，na2o为白色略黄状粉末，所以分子型氧化物是so3。
备注：原来经历过的事情都不会忘记；说忘记的，是一时半会记不起罢了，但仔细去回想却还是能想起来的，比如曾学到的知识、遇过的人以及此时囊中羞涩，兜里没钱，穷到吃土。
