Chapter 4

Why did Mendeleeff arrange the elements in the increasing order of their atomic weight in his periodic table?

How was the problem of placement of isotopes in Mendeleeff's periodic table overcome in the modern periodic table?

Why did Newland's law of octaves fail?

Why are the "s-" and "p-" blocks elements called representative elements?

General electronic configuration of s-block elements is

Describe the trend of oxidizing and reducing property along a period and a group of the periodic table.

Describe the trend of electron affinity along a period.

Describe the trend of atomic size along a period and a group in the periodic table.

Describe the trend of ionization potential along a period and a group in the periodic table.

Why are the chemical properties of the elements belonging to the same group similar?

Why is it that hydrogen can be placed in both I A group and VII A group of the modern periodic table?

What do you mean by representative elements? Give an example.

Which group contains the noble gases and what are the special characteristics of these gases?

General electronic configuration of chalcogens is

Describe the trend of ionization potential down the group in the periodic table.

Describe how the metallic and non-metallic characters vary along a period and group of the periodic table.

block elements can exhibit variable number of oxidation states.

What is a covalent radius?

In the long form of periodic table contains the maximum number of elements.

How does the electron affinity vary in the first transition series?

In the f-block elements differentiating electron enters into f-orbital of shell.

What are the merits of Mendeleeff's periodic table?

Why are the lanthanides and the actinides given a separate position in the modern periodic table?

Describe how effective nuclear charge changes along a period and a group in a periodic table.

Why are the values of the first, the second, the third ionization energies different from each other?

How does electron affinity vary in halogens?

What is the basic difference between Mendeleeff's periodic table and modern periodic table?

What is the difference between electronegativity and electropositivity?

Mention different categories of elements in the long form of the periodic table.

What is the difference between transition and inner transition elements?

How does filling of valence electrons takes place in p-block, d-block and f-block elements?

What are the merits and limitations of the long form of the periodic table?

Describe briefly Mendeleeff's periodic table along with its merits.

What are the limitations of Mendeleeff 's periodic table?

Explain briefly the periods of the modern periodic table.

Explain briefly about the groups of the modern periodic table and also classify the elements depending on electron filling in s-, p-, d- and f-subshells along with the position in the periodic table.