Final answer:
BeCl₂ exhibits the most covalent type of bond due to the small, highly charged Be cation, which has a high polarizing effect on the Cl anions, decreasing the electronegativity difference and enhancing covalent character.
Step-by-step explanation:
To determine which chloride exhibits the most covalent type of bond, we look at the electronegativity difference between the metal and the chlorine atom. The covalent character increases as the electronegativity difference decreases, and as the metal cation becomes smaller and has a higher charge density.
(A) NaCl and (B) KCl involve alkali metals, and usually form ionic bonds with chlorine. (C) CaCl₂ and (D) BaCl₂ also form ionic compounds, but because of their +2 charge, they have a chance for greater covalent character than NaCl or KCl. However, beryllium chloride, (E) BeCl₂, has a small Be cation with a +2 charge, leading to a higher covalent character due to polarizing power on the chlorine anions.
Therefore, (E) BeCl₂ is expected to exhibit the most covalent type of bond compared to the other chlorides listed.