Of the following compounds of calcium, the one having highest covalent character is A. CaF2 B. CaCl2 C. CaBr2 D. Cal3

The correct answer is A. CaF2.

The covalent character of a compound is determined by the difference in electronegativity between the atoms in the compound. The higher the difference in electronegativity, the more covalent the compound.

In CaF2, the electronegativity of calcium is 1.00 and the electronegativity of fluorine is 4.00. The difference in electronegativity is 3.00,

In CaCl2, the electronegativity of calcium is 1.00 and the electronegativity of chlorine is 3.00. The difference in electronegativity is 2.00.

In CaBr2, the electronegativity of calcium is 1.00 and the electronegativity of bromine is 2.80. The difference in electronegativity is 1.80.

In Cal3, the electronegativity of calcium is 1.00 and the electronegativity of argon is 2.55. The difference in electronegativity is 1.55.

Therefore, CaF2 has the highest covalent character.