How many valence electrons in each of the following?
7 valence electrons
If we complete the table below for a bromine atom it is
Valence electrons are those electrons in the outer most shell. In the case
of bromine the outer most shell is the n = 4 shell. There are 7 electrons
in the fourth shell; the 2 in the s subshell and the 5 in the p
subshell. Note the 3d electrons are inner core for bromine.