To determine which pair of elements would likely form the least polar bonds, we need to look at the difference in electronegativity between the pairs of elements. The smaller the difference in electronegativity, the less polar the bond.
Let's calculate the electronegativity differences for each pair:
-
Phosphorus (2.1) and Bromine (2.8):
- Difference = |2.8 - 2.1| = 0.7
-
Nitrogen (3.0) and Oxygen (3.5):
- Difference = |3.5 - 3.0| = 0.5
-
Oxygen (3.5) and Phosphorus (2.1):
- Difference = |3.5 - 2.1| = 1.4
-
Bromine (2.8) and Nitrogen (3.0):
- Difference = |3.0 - 2.8| = 0.2
Now, comparing the differences:
- Phosphorus and Bromine = 0.7
- Nitrogen and Oxygen = 0.5
- Oxygen and Phosphorus = 1.4
- Bromine and Nitrogen = 0.2
The pair with the smallest difference in electronegativity, which indicates the least polar bond, is Bromine and Nitrogen (0.2).
Therefore, the pair of elements that would likely form the least polar bonds with each other is:
bromine and nitrogen.