Question

MEDAL: How do I find the amount of valence electrons on a periodic table?

Answer 1

Use the group number for the main (representative) elements. Groups 1 and 2 have 1 and 2 valence electrons, respectively. For groups 13 to 18, subtract 10 from the group number to get the number of valence electrons. For example, carbon is in group 14. 14-10 = 4, so carbon has 4 valence electrons.

If you have a periodic table with the older roman numeral group numbers, the number of valence electrons is the same as the roman numeral for the "A" group elements.