Question

"$LiCl$ is covalent while $NaCl$ is ionic."
Answer whether the above statement is true or false.
If true enter 1, else enter 0.

Answer 1

The electronic configuration of $L{i}^{+}$ is $1s^2$. We know from the Schrödinger Wave Equation that the 1s Atomic Orbital is close to the nucleus and as result of the +3 charged nucleus, the $L{i}^{+}$ ion is anomalously small. Because of the high charge density (charge over radius), the $L{i}^{+}$ ion is able to polarize (distort) the electron cloud of neighboring anions. This is equivalent to saying that $L{i}^{+}$ salts have more covalent character. According to Fajan's rules $N{a}^{+}$ has a ionic radius of ~116 pm and the polarizing power is significantly less so there is less covalent character (but not zero) in $NaCl$. Therefore $LiCl$ is covalent while $NaCl$ is ionic.

Hence, the statement is true.