Embibe Experts Solutions for Chapter: Classification of Elements and Periodicity in Properties, Exercise 3: Level 3

The correct order of Pauling electronegativity is:

Among the elements $\mathrm{C},\mathrm{N},\mathrm{K}$ and $\mathrm{Mg}$, Which would show the greatest difference in first and second ionisation enthalpies?
 

Select equations having exothermic step:
 

How many of the following have greater ${\mathrm{Z}}_{\mathrm{eff}}$ than Silicon atom:

(i) $\mathrm{Na}$ (ii) $\mathrm{Mg}$ (iii) $\mathrm{Al}$ (iv) $\mathrm{P}$ (v) $\mathrm{Cl}$ (vi) $\mathrm{S}$ (vii) $\mathrm{N}$ (viii) $\mathrm{O}$ (ix) $\mathrm{F}$

Where $\mathrm{a}, \mathrm{b}, \mathrm{c}, \mathrm{d}, \mathrm{e}, \mathrm{f}, \mathrm{g}, \mathrm{h}$ are $3^{\mathrm{rd}}$ period elements. If the difference between the atomic numbers of elements $\mathrm{b}$ and $\mathrm{e}$ is $\mathrm{x}$ and the difference between the atomic number of elements $\mathrm{c}$ and $\mathrm{f}$ is $\mathrm{y}.$ What is the value of $\mathrm{x}-\mathrm{y}.$

The electron gain enthalpy of a hypothetical element $\text{'}\mathrm{A}\text{'}$ is $-3 \mathrm{eV}$ per atom. How much energy in $\mathrm{kCal}$ is released when $10 \mathrm{g}$ of $\text{'}\mathrm{A}\text{'}$ are completely converted to ${\mathrm{A}}^{-}$, ions in gaseous state ?  (Molar mass of $\mathrm{A}=30 \mathrm{g}$)

Find the total number of cations for which $I.P.$ of cation is lower than corresponding atom.${\mathrm{K}}^{+}, {\mathrm{O}}^{+}, {\mathrm{Ne}}^{+}, {\mathrm{P}}^{+}, {\mathrm{Be}}^{+}, {\mathrm{Na}}^{2+}, {\mathrm{Fe}}^{+}, {\mathrm{Sn}}^{2+}$

According to $I. C.$ Slater effective nuclear charge, $Z*,$ due to screening, is not exactly equal to the actual nuclear charge $Z$ of the nucleus of the atom.$Z*$ depends on the type of orbital In which the electron is housed, and on the ability of other electrons
in more penetrating orbitals to screen the electron in question from the nucleus.
The relative extent to which the various orbitals penetrate the electron clouds of other orbitals is$s>p>d>f.$ The effective nuclear charge $Z*$ due to screening is given by $Z^{*}=Z-\sigma$ where $Z$ is the atomic number and $\sigma$ is the slater screening constant values:$0<\sigma <Z$

Screening effect of one electron in the outermost orbital, is not considered in calculation of $\sigma .$

What is $Z^{*}$ for $\mathrm{Cu}\left(29\right)?$