# How do the number of valence electrons differ across a period?

Jun 15, 2017

And start a new Period, lithium ($\text{Group 1}$) has ONE valence electron; beryllium ($\text{Group 2}$) has TWO valence electrons; boron ($\text{Group 13}$) has THREE valence electrons; carbon ($\text{Group 14}$) has FOUR valence electrons......................