Question
Which of the following is not the correct order for the stated property ?
A.
$$Ba > Sr > Mg;$$ atomic radius
B.
$$F > O > N:$$ first ionization enthalpy
C.
$$Cl > F > I;$$ electron affinity
D.
$$O > Se > Te;$$ electronegativity
Answer :
$$F > O > N:$$ first ionization enthalpy
Solution :
On moving along the period, ionization enthalpy increases.
In second period, the order of ionization enthalpy should be as follows $$:F > O > N$$
But $$N$$ has half-filled structure, therefore, it is more stable than $$O.$$ That’s why its ionization enthalpy is higher than $$O.$$ Thus, the correct order of $$IE$$ is $$F > N > O.$$