问答题 What is electronegativity? Arrange the members of each of the following sets of elements in order of increasing electronegativities：
   (1)B，Ga，Al，In    (2)S，Na，Mg，Cl
   (3)P，N，Sb，Bi    (4)S，Ba，F，Si
【正确答案】EIectronegativity is a ability that a element’S atom attracted electron in a molecular.
   The order of increasing electronegativities are
   (1)In＜Ga＜Al＜B；
【答案解析】
【正确答案】Na＜Mg＜S＜Cl；
【答案解析】
【正确答案】Bi＜Sb＜P＜N；
【答案解析】
【正确答案】Ba＜Si＜S＜F。
【答案解析】