what are the observed periodic trends in electron affinity?
 The observed periodic trends in electron affinity are as follows: 1 For main-group elements, electron affinity generally becomes more negative as you move to the right across a row B. 2 For main-group elements, electron affinity generally becomes more positive as you move to the right across a row C. 3 There is not a corresponding trend in electron affinity going right across a row D. 4 For main-group elements, electron affinity generally becomes more negative as you move down a column. 