Given the following electronic configurations, identify how many valence electrons each atom has. A =
B =
C =
A 3-column table with 3 rows. Column 1 is labeled Element with entries Sodium (upper N a), Oxygen (upper O), and Iron (upper F e). Column 2 is labeled electron configuration with entries 1 s superscript 2, 2 s superscript 2, 2 p superscript 6, 3 s superscript 1; 1 s super 2; 2 s super 2, 2 p super 4; and 1 s super 2, 2 s super 2, 2 p super 6, e p super 6, 4 s super 2, 3 d super 6. Column 3 is labeled number of valence electrons with entries A, B, and C.