How does the periodic table indicate the number of valence electrons an element has?
A. By the group number of the B columns
B. By the group number of the A columns
C. By the row number
D. By the period number

B. By the group number of the A columns

Explanation:

Valence electrons which is a term that describes the number of electrons in the highest occupied energy level for an element helps to categories the elements into groups.

Hence, based on Chemical Abstracts Service, CAS grouping, it is shown or concluded that the periodic table indicate the number of valence electrons an element has by the group number of the A columns

when he becomes king

du boi was considered a radical because he wanted the immediate end for segregation. the biggest different between him and booker t. washington is that, even though washington believed that segregation should be considered illegal, he did not believe at all that a law was needed to keep blacks away from whites and that this would be something natural (to have the races apart) for a long time until society adjusted, while du boi believe that agitation was the only way to end segregation.