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