Periodic Trends in Properties

Using Slater's rule calculate the effective nuclear charge on a $3\mathrm{p}$ electron in aluminium and chlorine. Explain how these results relate to the atomic radii of the two atoms.

The electron gain enthalpy of chlorine is $348 \mathrm{kJ}{ \mathrm{mol}}^{-1}$. How much energy in $\mathrm{kJ}$ is released when $17.5 \mathrm{g}$ of chlorine is completely converted into ${\mathrm{Cl}}^{-}$ ions in the gaseous state?

A student reported the ionic radii of isoelectronic species ${\mathrm{X}}^{3+}, {\mathrm{Y}}^{2+}$ and ${\mathrm{Z}}^{-}$ as $136 \mathrm{pm}, 64 \mathrm{pm}$ and $49 \mathrm{pm}$ respectively. Is that order correct? Comment.

The first ionisation energy $\left({\mathrm{IE}}_1\right)$ and second ionisation energy $\left({\mathrm{IE}}_2\right)$ of elements $\mathrm{X}, \mathrm{Y}$and $\mathrm{Z}$ are given below:

Which one of the above elements is the most reactive metal, the least reactive metal and a noble gas?

What is screening effect? Briefly give the basis for Pauling's scale of electronegativity.

Explain giving appropriate reason, the formation of ${\mathrm{F}}^{-} \left(\mathrm{g}\right)$ from $\mathrm{F}\left(\mathrm{g}\right)$ is exothermic while that of ${\mathrm{O}}^{2-}\left(\mathrm{g}\right)$ from $\mathrm{O} \left(\mathrm{g}\right)$ is endothermic.

 Explain giving appropriate reasons, the electron affinity values of $\mathrm{Be}, \mathrm{Mg}$ and noble gases are zero and those of $\mathrm{N} (0.02 \mathrm{eV})$ and $\mathrm{P} (0.80 \mathrm{eV})$ are very low.

Explain giving appropriate reasons, first ionisation potential of $\mathrm{C}$-atom is greater than that of $\mathrm{B}$ atom, whereas the reverse is true is for second ionisation potential.

Ionisation potential of $\mathrm{N}$ is greater than that of $\mathrm{O}$. Explain giving appropriate reason.

By using Pauling's method calculate the ionic radii of ${\mathrm{K}}^{+} \mathrm{and} {\mathrm{Cl}}^{-}$ ions in the potassium chloride crystal. Given that ${\mathrm{d}}_{{\mathrm{K}}^{+}-{\mathrm{Cl}}^{-}} = 3.14 \stackrel{\circ }{\mathrm{A}}$.

Why the first ionisation enthalpy of sodium is lower than that of magnesium while its second ionisation enthalpy is higher than that of magnesium?

Explain the diagonal relationship.

Explain the periodic trend of ionisation potential.

Explain the Pauling method for the determination of ionic radius.

Mention any two anomalous properties of second period elements.

The electronic configuration of atom is one of the important factor which affects the value of ionisation potential and electron gain enthalpy. Explain.

Energy of an electron in the ground state of the hydrogen atom is $-2.8\times {10}^{-18} \mathrm{J}$. Calculate the ionisation enthalpy of atomic hydrogen in terms of $\mathrm{kJ} {\mathrm{mol}}^{-1}$.

How would you explain the fact that the second ionisation potential is always higher than first ionisation potential?

Define electronegativity.

Magnesium loses electrons successively to form ${\mathrm{Mg}}^{+}, {\mathrm{Mg}}^{2+}$ and ${\mathrm{Mg}}^{3+}$ ions. Which step will have the highest ionisation energy and why?