Periodic Trends and Chemical Reactivity of Elements

The ions  ${\mathrm{O}}^{2-},{\mathrm{F}}^{-},{\mathrm{Na}}^{+},{\mathrm{Mg}}^{2+}\mathrm{and}{\mathrm{Al}}^{3+}$ are isoelectronic. Their ionic radii show:

The atomic number of Vanadium $\left(\mathrm{V}\right)$, Chromium $\left(\mathrm{Cr}\right)$, Manganese $\left(\mathrm{Mn}\right)$ and Iron $\left(\mathrm{Fe}\right)$ are, respectively, $23, 24, 25 \mathrm{and} 26$. Which one of these may be expected to have the highest second ionization enthalpy?

Lithium shows diagonal relationship with element '$\mathrm{X}$' and aluminum with $\mathrm{Y}.\mathrm{X}$ and $\mathrm{Y}$ respectively are

In second period of the long form of the periodic table, an element $\mathrm{X}$ has second lowest first ionization enthalpy and element $\mathrm{Y}$ has second highest first ionization enthalpy values. What are $\mathrm{X}$ and $\mathrm{Y}$ ?

In which of the following, elements are arranged in the correct order of their electron gain enthalpies.

The successive ionization energies of an element, in $\mathrm{kJ}·{\mathrm{mol}}^{-1}$ are $1060,1900, 2920, 6280$ and $21200.$ This element would belong to group- $\underline{ }$

Which order among the following is incorrect ?

Which element among the following is most probable to have the following values?

${\mathrm{\Delta }}_{\mathrm{i}}{\mathrm{H}}_1=419 \mathrm{kJ}{ \mathrm{mol}}^{-1}$
${\mathrm{\Delta }}_{\mathrm{i}}{\mathrm{H}}_2=3051 \mathrm{kJ}{ \mathrm{mol}}^{-1}$
${\mathrm{\Delta }}_{\mathrm{eg}}\mathrm{H}=-48 \mathrm{kJ}{ \mathrm{mol}}^{-1}$

Identify the correct order of ionic radii of the given species:

If the successive ionization energies of an element $\mathrm{A}$ are $165, 190, 550$ and $595\mathrm{kcal},$ respectively, then the ground state electronic configuration of element $\mathrm{A}$ is

Which of the following sequences is the correct order of the size of species?

Which among the following iso-electronic species has the smallest size?
${\mathrm{O}}^{2-}, {\mathrm{F}}^{-}, \mathrm{Ne}, {\mathrm{Na}}^{+}, {\mathrm{Mg}}^{2+}, {\mathrm{Al}}^{3+}, {\mathrm{Si}}^{4+}$

The ions ${\mathrm{S}}^{2-}, {\mathrm{Cl}}^{-}, {\mathrm{K}}^{+}, {\mathrm{Ca}}^{2+}$ are iso-electronic. Their ionic radii show $\_\_\_\_\_\_\_$

Identify the incorrect order corresponding the mentioned property?

Effective nuclear charge is maximum in case of ________

Arrange $\mathrm{B}\mathrm{e},\mathrm{}\mathrm{M}\mathrm{g},\mathrm{}\mathrm{C}\mathrm{a},\mathrm{}\mathrm{S}\mathrm{r}$ in the ascending order of ionisation enthalpy.