How does the number of valence electrons change from left to right across the periodic table?
1 Answer
Aug 24, 2016
The number of valence electrons goes up by one each time you move another column (group) to the right.
Explanation:
There are a few things to look out though when trying to figure out the number of valence electrons.
Group 1 elements have one valence electrons, and Group 2 elements have 2 valence electrons. Groups 13-17 have 3,4,5,6 & 7 valence electrons respectively. The noble gases (group 18) have 8 valence electrons except for He which has only 2 valence electrons.
Elements in groups 3-12 are referred to as the transition metals and there are more exceptions to rules for determining valence electrons for these elements.
Here is a video review of Lewis structures and valence electrons.
Hope this helps!
