S C Kheterpal, S N Dhawan and, P N Kapil Solutions for Chapter: Classification of Elements and Periodicity in Properties, Exercise 9: ADDITIONAL QUESTIONS

Explain the following : Ionisation enthalpy of nitrogen is more than that of oxygen.

In the following pair, state which atom/ion has higher ionisation enthalpy and more negative electron gain enthalpy.

$\mathrm{Br}, {\mathrm{Br}}^{-}$.

In the following pair, state which atom/ion has higher ionisation enthalpy and more negative electron gain enthalpy? 

$\mathrm{Li}, {\mathrm{Li}}^{+}$

In the following pair, state which atom/ion has higher ionisation enthalpy and more negative electron gain enthalpy?

 $\mathrm{Br}, \mathrm{I}$

Name the four blocks of elements in the periodic table and indicate the main difference in their electronic configurations. Give examples of each type. State at least four characteristics of each block.

Explain what you understand by covalent radius, van der Waals radius, ionic radius and atomic radius. How do they vary in a period and in a group?

Define ionisation enthalpy and successive ionisation enthalpies. Discuss the factors that influence the magnitude of ionisation enthalpy. What are the general trends of variation of ionisation enthalpy in the periodic table ? Explain.

Define electron gain enthalpy. Describe the factors which determine the magnitude and sign of electron gain enthalpy. What are the general trends of variation of electron gain enthalpies in the periodic table?