If Bromine belongs to the group halogens in group 7a, what do you know about the valence electrons and how reactive bromine is with other elements?

it has 7 electrons and it react to the elements with only 1 valence electron, which are elements in group 1

Explanation:

answer; i do believe the correct answer is (river); /// good luck

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8