In comparison to boron, beryllium has:

Given below are the oxides :

${\mathrm{Na}}_2\mathrm{O},{\mathrm{As}}_2{\mathrm{O}}_3,{\mathrm{N}}_2\mathrm{O},\mathrm{NO}$ and ${\mathrm{Cl}}_2{\mathrm{O}}_7$ Number of amphoteric oxides is :

What is the correct oder of electron gain enthalpy of $\mathrm{Cl}, \mathrm{F}, \mathrm{Te}, \mathrm{Po}$

Given below are two statements : one is labelled as Assertion and the other is labelled as Reason.

Assertion: The ionic radii of ${\mathrm{O}}^{2-}$ and ${\mathrm{Mg}}^{2+}$ are same.

Reason: Both ${\mathrm{O}}^{2-}$ and ${\mathrm{Mg}}^{2+}$ are isoelectronic species.

In the light of the above statements, choose the correct answer from the options given below.

Given below are two statements. One is labelled as
Assertion $\mathrm{A}$ and the other is labelled as Reason $\mathrm{R}$.
Assertion $\mathrm{A}$ : The first ionization enthalpy for oxygen is lower than that of nitrogen.

Reason $\mathrm{R}$ : The four electrons in $2\mathrm{p}$ orbitals of oxygen experience more electron-electron repulsion.

In the light of the above statements, choose the correct answer from the options given below.