Br - (36) 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6

Bromine (BR) 1s (1) 2s (2) p (6), 3s (2) p (6),3d (10) 4s (2), p (5)

Explanation:

Group 7A elements have a - 1 electron configuration.

Beginning at the top left and going across the rows of the periodic table provides a method for remembering the order

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p.