Which of the following is a Lewis acid?

$BX_3 + NH_3 \xrightarrow{R.T} BX_3 \cdot NH_3 + \text{Heat of adduct formation } (\Delta H)$. The numerical value of $\Delta H$ is found to be maximum for

Observe the following statements:
$i$. The dipole moment of $NH_3$ is higher than the dipole moment of $NF_3$.
$ii$. The dipole moment of chloroform $(CHCl_3)$ is zero.
$iii$. Covalent bond character in $NaCl$ is more compared to $CuCl$.

What is an ionic bond? With two suitable examples,explain the difference between an ionic and a covalent bond.

Which of the following bonds has the highest bond energy?

Chemical bond implies