What trend in valence electrons is there among the main-group elements?
A. All of the elements in a period have the same number of valence
electrons.
B. The number of valence electrons increases by 1 for each element
as you move from left to right across a period.
C. The number of valence electrons decreases by 1 for each element
as you move from left to right across a period.
D. The number of valence electrons is random, and there is no trend.