Answer : The correct option is, 
Explanation :
The given element bromine belongs to the group 17 and period 4. The symbol of bromine is, Br.
The atomic number of bromine = 35
The total number of electrons present in bromine element = 35
Electronic configuration : It is defined as the arrangement of electrons around the nucleus of an atom.
Hence, the correct electronic configuration of bromine is,

8.38e -21Q^2 -1.07e -23Q^2 +3.15e +19
= 10.46e -44Q^2 + 19
44Q^2 = 10.46e + 19
Q^2 = 523/2200e + 19/44
Q1= ≈ -1.03828
Q2= ≈ 1.03828
What do you need help on which problem
They have six valence electrons