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。