Which of the following elements has the highest electronegativity?

Arrange the following bonds in order of increasing ionic character: $C-O, C-N$ and $C-C$. Give reasons.

The electronegativity of the following elements increases in the order:

For $AB$ bond,if percent ionic character is plotted against electronegativity difference $(X_A - X_B)$,the shape of the curve would look like. The correct curve is:

Arrange the following elements in increasing order of electronegativity:
$N, O, F, C, Si$
Choose the correct answer from the options given below:

Among the following,the pairs of elements having approximately the same electronegativity values are:
$I$. $H$ and $P$
$II$. $Be$ and $Al$
$III$. $N$ and $Cl$
$IV$. $C$ and $P$