With increasing atomic number in a certain period:

Which of these has no unit?

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

Fluorine is a better oxidizing agent than $Br_2$ because of........

Which of the following statements is incorrect?

Given below are two statements:
Statement $I$: The correct order of electronegativity of fluorine, oxygen and nitrogen is $F > O > N$.
Statement $II$: The oxidation state of oxygen in $OF_2$ is $+2$ and in $Na_2O$ is $-2$.