Answer:
During a chemical reaction, Bromine (Br) would be expected to gain 1 valence electron to have a full octet.
Step-by-step explanation:
In the periodic table the elements are ordered so that those with similar chemical properties are located close to each other.
The elements are arranged in horizontal rows, called periods, which coincide with the last electronic layer of the element. That is, an element with five electronic shells will be in the fifth period.
The columns of the table are called groups. The elements that make up each group coincide in their electronic configuration of valence electrons, that is, they have the same number of electrons in their last.
The elements tend to resemble the closest noble gases in terms of their electronic configuration of the last layer, that is, having eight electrons in the last layer to be stable.
Bromine belongs to group 17 (VII A), which indicates that it has 7 electrons in its last shell. So bromine requires more energy to lose all 7 electrons and generate stability, than it does to gain 1 electron and fill in 8 electrons to be stable. So:
During a chemical reaction, Bromine (Br) would be expected to gain 1 valence electron to have a full octet.