To determine if the bond in hydrogen bromide (HBr) is polar or nonpolar, we can look at the electronegativity values of the two atoms involved: hydrogen (H) and bromine (Br).
Electronegativity is a measure of how strongly an atom attracts electrons in a bond. The electronegativity of hydrogen is approximately 2.1, while the electronegativity of bromine is about 2.8. To assess the polarity of the bond, we can calculate the difference in electronegativity:
- Electronegativity of Br: 2.8
- Electronegativity of H: 2.1
- Difference: 2.8 – 2.1 = 0.7
A bond is generally considered polar if the difference in electronegativity is between 0.4 and 1.7. Since the difference of 0.7 falls within this range, we conclude that the H-Br bond is indeed polar.
This polarity arises because bromine, being more electronegative, pulls the bonding electrons closer to itself, resulting in a partial negative charge on the bromine atom and a partial positive charge on the hydrogen atom. Therefore, HBr is a polar molecule, and this property influences its behavior in chemical reactions and interactions with other molecules.