MEDIUM
11th CBSE
IMPORTANT
Earn 100

How does atomic radius vary in a period and in a group? How do you explain the variation?

Important Questions on Classification of Elements and Periodicity in Properties

EASY
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.11
What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions.
(i)  F- (ii) Ar (iii) Mg2+ (iv) Rb+
EASY
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.12

Consider the following species :

N3-, O2-, F-, Na+, Mg2+ and Al3+ 

What is common in them?

HARD
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.12

Consider the following species :

N3-, O2-, F-, Na+, Mg2+ and Al3+ 

Arrange them in the order of increasing ionic radii.

EASY
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.13
Explain why cations are smaller and anions larger in radii than their parent atoms?
MEDIUM
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.14

What is the significance of the terms — ‘isolated gaseous atom’ and ‘ground state’ while defining the ionization enthalpy and electron gain enthalpy?

Hint: Requirements for comparison purposes.

MEDIUM
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.15
Energy of an electron in the ground state of the hydrogen atom is -2.18×10-18J. Calculate the ionization enthalpy of atomic hydrogen in terms of J mol‐1. 
MEDIUM
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.16
Among the second period elements the actual ionization enthalpies are in the order Li < B < Be < C < O < N < F < Ne.
Explain why Be has higher ∆iH than B
 
HARD
11th CBSE
IMPORTANT
Textbook for Class XI Chemistry Part I>Chapter 3 - Classification of Elements and Periodicity in Properties>EXERCISES>Q 3.16
Among the second period elements the actual ionization enthalpies are in the order Li < B < Be < C < O < N < F < Ne.
Explain why O has lower ∆iH than N and F?