Answer:
Chlorine
Explanation:
The Polarity of an atom is characterized as the dipole to dipole intermolecular forces between the slightly positively-charged end of one molecule to the negative end of another or the same molecule. Thus, the 'chlorine' atom would help in enhancing the polarity of hydrogen bromide(HBr) with 3.16 electronegativity as we know, the electronegativity increases if we move upwards in the periodic table.
