Sahana Ansari and Neha Miglani Solutions for Chapter: Classification of Elements and Periodicity in Properties, Exercise 5: Chapter Practice

What is the cause of periodicity in the properties of elements? How do the following properties vary in a (a) group, (B) period?

Ionization energy

Arrange the given elements. 

$\mathrm{H}, \mathrm{He}, \mathrm{Li}, \mathrm{Be}, \mathrm{B}, \mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}, \mathrm{Ne}, \mathrm{Na}, \mathrm{K}, \mathrm{Rb}, \mathrm{Cs}.$

In the order of decreasing size in the period.

Arrange the given elements. $\mathrm{H}, \mathrm{He}, \mathrm{Li}, \mathrm{Be}, \mathrm{B}, \mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}, \mathrm{Ne}, \mathrm{Na}, \mathrm{K}, \mathrm{Rb}, \mathrm{Cs}.$

In the order of increasing metallic character in the group.

Arrange the given elements. $\mathrm{H}, \mathrm{He}, \mathrm{Li}, \mathrm{Be}, \mathrm{B}, \mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}, \mathrm{Ne}, \mathrm{Na}, \mathrm{K}, \mathrm{Rb}, \mathrm{Cs}.$

In the order of increasing electronegativity in the period.

Arrange the following as stated:Increasing order of basic character;

$\mathrm{MgO}, \mathrm{SrO}, {\mathrm{K}}_2\mathrm{O}, \mathrm{NiO}, {\mathrm{Cs}}_2\mathrm{O}.$

Arrange the following as stated:Increasing the first ionization energy:

$\mathrm{Mg}, \mathrm{Al}, \mathrm{Si}, \mathrm{Na}.$

Arrange the following as stated: Increasing acidity property: $\mathrm{ZnO}, {\mathrm{Na}}_2{\mathrm{O}}_2, {\mathrm{P}}_2{\mathrm{O}}_5, \mathrm{MgO}.$

Explain what is meant by the ionisation energy of an element. How does this vary between hydrogen and neon in the periodic table? Discuss how the variation can be related to the electronic structure of the atoms.