Which of the following has
a. the most polar bond?
b. the least polar bond?
NaI LiBr Cl₂ KCl

Verified step by step guidance

1. Step 1: Understand the concept of bond polarity. Bond polarity arises due to the difference in electronegativity between two atoms in a bond. The greater the electronegativity difference, the more polar the bond.
2. Step 2: Identify the electronegativity values of the elements involved. Use the periodic table to find the approximate electronegativity values: Na (0.93), I (2.66), Li (0.98), Br (2.96), Cl (3.16), and K (0.82).
3. Step 3: Calculate the electronegativity difference for each bond: NaI, LiBr, Cl2, and KCl. For example, for NaI, subtract the electronegativity of Na from I: |2.66 - 0.93|. Repeat this for the other bonds.
4. Step 4: Compare the electronegativity differences. The bond with the largest electronegativity difference will be the most polar, and the bond with the smallest electronegativity difference will be the least polar.
5. Step 5: Note that Cl2 is a bond between two identical atoms, so its electronegativity difference is zero, making it nonpolar. Use this information to determine which bond is the least polar and which is the most polar.

Key Concepts

Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons in a chemical bond. The greater the difference in electronegativity between two bonded atoms, the more polar the bond becomes. For example, in a bond between sodium (Na) and iodine (I), the significant difference in their electronegativities results in a highly polar bond.

Ionic vs. Covalent Bonds

Bonds can be classified as ionic or covalent based on the nature of the electron sharing. Ionic bonds occur between metals and nonmetals, where electrons are transferred, leading to charged ions. Covalent bonds involve the sharing of electrons between nonmetals. The type of bond influences the polarity, with ionic bonds generally being more polar than covalent bonds.

Bond Polarity

Bond polarity refers to the distribution of electrical charge across a bond. A polar bond has a significant difference in electronegativity between the two atoms, resulting in partial positive and negative charges. In contrast, nonpolar bonds, like Cl2, have equal sharing of electrons, leading to no charge separation. Understanding bond polarity is crucial for determining the most and least polar bonds among the given compounds.