Lithium halides are somewhat …A… It is because …B… value of polarization capability of lithium ion. Here, A and B refer to

The alkali metals readily react vigorously with halogens to form ionic halides, M+X-. However, lithium halides are somewhat covalent. It is because of the high polarization capability of lithium ion. The distortion of electron cloud of the anion by the cation is called polarization. The Li⁺ ion is very small in size and high tendency to distort electron cloud around the negative halide ion. Since anion with large size can be easily distorted, among halides, lithium iodide is the most covalent in nature.