Chapter 3 - Classification of Elements and Periodicity in Properties

In this chapter, you’ll study the periodic table and its interesting development from ancient times till date – what we call as the ‘Modern Periodic Table’. The periodic table is nothing but a categorisation of chemical elements arranged based on their electronic configuration of atoms. You’ll learn about the initial grouping of elements, eventually leading to the development of the periodic table. You’ll also get to know what periodic law is, the importance of atomic number, elements with z.100 based on the IUPAC nomenclature. You’ll also study the classification of elements based on s,p,d,f blocks and identify their properties.

Thus, an in-depth study of Class 11 Chemistry NCERT Solutions Chapter 3 will give you a clear understanding of the modern periodic table and its elements.

Let’s take a look at topics and sub-topics of Class 11 Chemistry Chapter 3, Classification of Elements and Periodicity in Properties.

3.1 Why do we Need to Classify Elements?

3.2 Genesis of Periodic Classification

3.3 Modern Periodic Law and the present form of the Periodic Table

3.4 Nomenclature of Elements with Atomic Numbers > 100

3.5 Electronic Configurations of Elements and the Periodic Table

3.6 Electronic Configurations and Types of Elements: s-, p-, d-, f- Blocks

3.6.1 The s-Block Elements

3.6.2 The p-Block Elements

3.6.3 The d-Block Elements (Transition Elements)

3.6.4 The f-Block Elements (Inner-Transition Elements)

3.6.5 Metals, Non-metals and Metalloids

3.7 Periodic Trends in Properties of Elements

3.7.1 Trends in Physical Properties

3.7.2 Periodic Trends in Chemical Properties

3.7.3 Periodic Trends and Chemical Reactivity

In Class 11 Chemistry Chapter 3, you will learn –

Section 3.1 – In this section, you’ll learn about elements and their importance. You’ll also come across the number of elements discovered on earth till date and the need to have a systematic periodic table to study the properties of various elements in a more rational way.

Section 3.2 – In this section, you will study about the propositions made by the German chemist – Johann Dobereiner and the English chemist – John Alexander Newlands. You’ll come across new terms like triads, the law of triads, octaves and the Law of Octaves. Further, in this section, you’ll study the Periodic Law as designed by the Russian chemist – Dmitri Mendeleev and the German chemist, Lothar Meyer. You’ll also explore some important Mendeleev’s Predictions for the Elements Eka-aluminium (Gallium) and Eka-silicon (Germanium).

Section 3.3 – In this section, you’ll acquire knowledge about the Modern Periodic Law that unveils significant analogies among the 94 naturally occurring elements.

Section 3.4 – In this section, you’ll learn notation for IUPAC Nomenclature of Elements with an atomic number above 100. It is good to know that till date, elements with atomic numbers up to 118 have been discovered. You’ll learn how once the element is found, it is initially given a temporary name and then a permanent name as decided by the IUPAC.

Section 3.5 – In this section, you will observe a direct connection between the electronic configurations of the elements and the long form of the Periodic Table. You’ll study the electronic configurations in periods and also the group-wise electronic configurations. You’ll come across new terms like a shell, orbitals, transition series and more.

Section 3.6 – In this section, you’ll study the electronic configurations and types of elements: s-, p-, d-, f- Blocks. You’ll also learn about metals, non-metals and metalloids. You’ll acquire knowledge about new terms like noble gases, halogens, chalcogens, transition elements, lanthanoids, actinoids and transuranium elements.

Section 3.7 – In this section, you’ll observe various patterns in the physical and chemical properties of elements while moving across a period in the Periodic Table. You’ll also learn about the various criteria taken into consideration while grouping the elements in the periodic table. Some of them are – melting and boiling points, heats of fusion and vaporisation, the energy of atomisation, atomic radius, ionic radius, ionisation enthalpy, electron gain enthalpy and electronegativity.

In this chapter, you are provided with several examples with their solutions for clear understanding about Classification of Elements and Periodicity in Properties. To know more about NCERT Solutions for Class 11 Chemistry Chapter 3, you should explore the exercises mentioned in this chapter. You can also download the NCERT Solutions for Class 11 Chemistry Chapter 3 PDF, solved by our science experts.