Class 11 · Chemistry · Chapter 3
Classification of Elements and Periodicity in Properties
This chapter tells the story of how chemists organised the 118 known elements into the modern Periodic Table — from Dobereiner's triads and Newlands' octaves to Mendeleev's brilliant predictions and the modern periodic law based on atomic number. You'll learn how the electronic configuration of an atom decides its position in the s-, p-, d-, or f-block, and then dive deep into the five big periodic trends — atomic radius, ionic radius, ionization enthalpy, electron gain enthalpy, and electronegativity. The chapter closes with periodicity in chemical properties (valence, oxide character, anomalous behaviour of the second period, and diagonal relationships) — a high-yield area for both Board exams and JEE/NEET.
Topics in this chapter
- 1
Introduction & Early Attempts at Classification
Quiz included
- 2
Mendeleev's Periodic Table & the Modern Periodic Law
Quiz included
- 3
Present Form of the Periodic Table & Nomenclature of Super-heavy Elements
Quiz included
- 4
Electronic Configurations & the s-, p-, d-, f-Block Classification
Quiz included
- 5
Types of Elements — Metals, Non-metals, Metalloids & Noble Gases
Quiz included
- 6
Periodic Trend — Atomic Radius
Quiz included
- 7
Ionic Radius & Isoelectronic Species
Quiz included
- 8
Ionization Enthalpy
Quiz included
- 9
Electron Gain Enthalpy
Quiz included
- 10
Electronegativity
Quiz included
- 11
Periodic Trends in Chemical Properties — Valence, Oxides & Anomalous Behaviour
Quiz included
- 12
Solved Examples
- 13
Strategic Exam Masterclass: JEE, NEET & Other Competitive Exams
Quiz included
- 14
Summary