Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: The first ionization enthalpy of O is lower than that of N and F .

Reason R: The loss of an electron from O leads to stable half-filled $p$ orbital

In light of the above statements, choose the most appropriate answer from the options given below:

The correct order of increasing metallic character of $\mathrm{Na}, \mathrm{Be}, \mathrm{P}, \mathrm{Mg}$ and Si is

Identify the incorrect statement from the following :

Which of the following statements are true?

A. Unlike Ga that has a very high melting point, Cs has a very low melting point.

B. On Pauling scale, the electronegativity values of N and Cl are not the same.

C. $\mathrm{Ar}, \mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}$, and $\mathrm{S}^{2-}$ are all isoelectronic species.

D. The correct order of the first ionization enthalpies of $\mathrm{Na}, \mathrm{Mg}, \mathrm{Al}$, and Si is $\mathrm{Si}>\mathrm{Al}>\mathrm{Mg}>\mathrm{Na}$.

E. The atomic radius of Cs is greater than that of Li and Rb.

Choose the correct answer from the options given below :