1.L'ion bromure est formé à partir de l'atome de brome Br qui a gagné un électron. Comment le note-t-on ?

1. Bromide ion is formed from the bromine atom Br which has gained an electron. How do we know?

Explanation:

To form a bromide ion, a bromine atom must have gained an electron.

Because elements in the bromine group has seven electrons in the outer shells of their atoms, the elements are all univalent. Bromine will gain one electron to complete its octet. This leaves a net negative charge on the atom. The number of protons in this specie is now lesser than the number of electrons. This differences leaves a negative charge on atom.