What are the observed periodic trends in electron affinity? check all that apply. check all that apply. for main-group elements, electron affinity generally becomes more negative as you move to the right across a row for main-group elements, electron affinity generally becomes more positive as you move to the right across a row there is not a corresponding trend in electron affinity going right across a row for main-group elements, electron affinity generally becomes more negative as you move down a column for main-group elements, electron affinity generally becomes more positive as you move down a column there is not a corresponding trend in electron affinity going down a column