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NCERT Solutions Class 11 Chemistry - Chapter 3

JEE Mains & Advanced

NCERT Solutions Class 11 Chemistry - Chapter 3 deals with solutions of questions in the exercise of the chapter classification of Elements and Periodicity in Properties. NCERT Solutions for Chapter 3 will help you get a better grasp of the concepts covered. These solutions cover all the important topics with in-depth explanations. With the help of these solutions, you'll learn how the periodic table was created and how the periodic law works. If you're getting ready for your Class 11 exams, these solutions can help you get good marks, which are developed by eSaral’s expert teachers 

After studying the chapter, Classification of Elements and Periodicity in Properties, you will able to

  • Recognize how the idea of grouping elements according to their properties resulted in the creation of the periodic table

  • Recognize the importance of the periodic table

  • Understand the periodic law

  • Understand the importance of the atomic number and electronic configuration as a basis for periodic classification

  • Understand how elements are classified into s,p,d,f blocks and their major properties

  • Understand periodic trends in physical and chemical properties of elements

  • Understand how element reactivity compares to their occurrence in nature

  • Understand the relationship between electronegativity and metallic character

  • Understand the scientific vocabulary

  • Adequately conveying ideas related to important properties of atoms such as atomic/ion radii, enthalpy, electron gain, valence of elements etc.

NCERT Solutions for Class 11 Chemistry Chapter 3 Sections

Section Name

Topic Name


Classification of elements and periodicity in properties


Why do we need to classify elements?


Genesis of periodic classification


Modern periodic law and the present form of the periodic table


Nomenclature of elements with atomic numbers > 100


Electronic configuration of elements and the periodic table


Electronic configuration and types of elements: s-, p-, d-, f- blocks 


Periodic trends in properties of elements

3.1 Why do we need to classify elements?: The classification of elements is essential for a variety of reasons, one of which is to facilitate the classification and classification of the large number of chemical substances present in nature.

3.2 Genesis of periodic classification: The periodic table of elements has a long and storied history, with lots of different scientists contributing to it. It's an amazing journey to figure out how elements are arranged.

3.3  Modern periodic law and the present form of the periodic table: The periodic law is basically saying that elements' physical and chemical behavior is a function of their atomic number. It's been around since 1913, but it's been around for a while now. Originally, it was thought that elements could only be organized according to their atomic weights, but Moseley did some research using X-rays and discovered that the atomic number in the nucleus is actually the most important thing that determines how elements behave in the periodic system.

3.4 Nomenclature of elements with atomic numbers > 100: Transactinide elements, also known as superheavy elements or transactinides, are elements with atomic numbers over 100. Superheavy elements are usually created by high-energy nuclei being bombarded at high velocities by particle accelerators. Because these elements are synthetic and unstable, naming them can be a laborious process that requires international cooperation and guidance from IUPAC.

3.5 Electronic configuration of elements and the periodic table: Electron configuration describes the number of electrons in the energy level and orbital around an atom’s nucleus. Electron configurations play an important role in determining elements’ chemical properties and behavior. The periodic table follows the principles of electron configuration, and understanding electron configurations helps explain the periodic table trends and patterns. 

  • Electronic configuration in period
  • Groupwise electronic configuration

3.6 Electronic configuration and types of elements: s-, p-, d-, f- blocks: Elementary structure is determined by the distribution of electrons in shell energy levels and orbital sublevels around an atom's nucleus. These configurations are classified into distinct blocks in the periodic table, which are based on the most recent electron added to an element's configuration. The primary blocks are s-blocks, p-blocks, d-blocks, and f-blocks, each representing a particular sublevel in the electronic configuration.

       In this section, following subtopics will be discussed

        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)

3.7 Periodic trends in properties of elements: In the periodic table, periodic trends are the trends that occur as elements are added to the periodic table as their atomic number increases. These trends allow us to see how elements' properties change as they move from period (rows) or group (columns).

      In this section, following subtopics will be discussed

       3.7.1 Trends in physical properties

       3.7.2  Periodic trends in chemical properties

       3.7.3 periodic trends and chemical reactivity

Key Points of Class 11 Chemistry NCERT Solutions Chapter 3

  • Mendeleev's Periodic Table was created on the basis of atomic masses. In the Modern Periodic Table, the elements are arranged in the sequence of their atomic number (periods) in 7 horizontal rows (groups or families) and 18 vertical columns (units). In a period, the atomic numbers are ordered in ascending order, whereas in a group they are ordered in descending order. The elements of the same group share the same valence shell electronic configuration, so they have similar chemical properties.

  • However, the elements in the same period have a gradually increasing number of electrons from left to right, so their valencies are different. You can recognize four types of elements in the periodic table based on their electronic configurations: s-blocks, p-blocks, d-blocks and f-blocks.

  • More than 78% of all known elements are metals, while the other 25% are nonmetals. The elements that lie at the boundary between metals and nonmetals (for example Si, Ge and As) are referred to as metalloids or semimetals. The metallic character increases as the atomic number increases in a group, while the non-metallic character decreases as the atomic number decreases in a period. Physical and chemical properties change periodically with their atomic number.

  • At the two extremes of a period, chemical reactivity is the highest, and at the other extreme, it's the lowest. On the left-hand side of a period, reactivity is the lowest because it's easy to lose electrons (or because it has a low ionization energy). High-reactivity elements don't exist naturally in free state - they usually come in a combined form. The elements formed by the left-hand elements are basic, and the elements formed by the right-hand ones are acidic. The oxides of the right-hand elements are amphoteric, and those of the center are neutral.

Benefits of Downloading the PDF of NCERT Solutions Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties

Students can benefit from downloading NCERT solutions for class 11 chemistry chapter 3 classification of elements and periodicity in properties. Here are some advantages that students can benefit from using NCERT solutions:

Accurate and comprehensive solutions: By downloading NCERT solutions from eSaral, students can get accurate and comprehensive answers to the questions in the chapter. This ensures that the answers given in the chapter are correct and match the concepts taught in the class.

In-depth explanation: By downloading the NCERT solutions, students can get detailed explanations of the concepts, theories and problem solving steps. This helps in understanding not only the answers, but also the principles behind them.

Concept clarity: In Chapter 3, the periodic table is discussed and its importance. By downloading eSaral’s solutions, students can break complex concepts down into simpler terms, improving their understanding and clarity.

Practice and Revision: eSaral’s solutions are a great tool for practice and revision. When students solve these solutions, they can consolidate their knowledge of a particular chapter and revise it effectively.

Time Management: Solving questions efficiently with eSaral’s solutions will help students better manage their time during exams by teaching them how to set aside the appropriate amount of time for each kind of question.

Frequently Asked Questions

Question 1: what are periods and groups in the periodic table?

Answer 1: In the periodic table, horizontal rows are periods the and vertical columns are the groups. The elements in the same period share the same number of shell valence electrons, and the elements within the same group share the same chemical properties.

Question 2: What are the anomalous properties observed in certain elements?

Answer 2: there is an exception that occurs when an element’s electron configuration causes deviations from predicted trends. For instance, half filled and full filled subshells cause variations in ionization energies and electron affinity.