4. Structure of The Atom-Electronic Configuration And valency Science Class 9 In English-CBSE Notes
Explore science cbse notes for Class 9 Chapter 4. Structure of The Atom Topic Electronic Configuration And valency in English medium for exams preparation.
4. Structure of The Atom-Electronic Configuration And valency Science Class 9 In English-CBSE Notes
Popular Topics Covered
Our study material includes
- cbse notes for class 9 science chapter 4. Structure of The Atom topic Electronic Configuration And valency in english
- class 9 science chapter 4. Structure of The Atom cbse notes
- cbse class 9 science chapter 4. Structure of The Atom notes in english
- class 9 science chapter 4. Structure of The Atom study notes
- class 9 science chapter 4. Structure of The Atom revision notes
- cbse notes for class 9 science chapter 4. Structure of The Atom
- class 9 science chapter 4. Structure of The Atom summary notes
- cbse class 9 science chapter 4. Structure of The Atom quick notes
All Topics Chapter 4. Structure of The Atom
- 1. Non-atomic particles
- 2. Model of An Atom
- 3. Electronic Configuration And valency
- 4. Isotopes And Isobar
- 5. page 5
Notes
4. Structure of The Atom-Electronic Configuration And valency Science Class 9 In English-CBSE Notes
4. Structure of The Atom
Electronic Configuration And valency
Chapter 4. Structure of The Atom
Energy Levels : There are various and definite orbits around the nucleus of an atom to revolve the electrons. These orbits or shells are called energy levels.
Energy Levels in An Atom
Electronic Configuration: The distribution of electrons in various and discrete shells of an atom is known as electronic configuration. The maximum numbers of electrons are difinite in each shell.
The Electronic Structure of Hydrogen:
Hydrogen has only one electron, so that it's outer shell is K and has only one electron.
The Electronic Structure of Carbon Atom:
Carbon atom has total 6 electrons. In which it has 2 electrons in its inner most shell K and 4 electrons in outer most shell L.
These are shells:
K, L, M, N etc.
Number of maximum electron in various shell:
Shell K can have maximum 2 electrons.
Shell L can have maximum 8 electrons.
Shell M can have maximum 18 electrons and
Shell N can have maximum 32 electrons.
There is used a formula to keep maximum electron in each shell : 2n2
On the basis of this formula, the maximum electrons in a shell is found.
Example, For the first shell K : 2(1)2 = 2 x 1 = 2
For the second shell L : 2(2)2 = 2 x 4 = 8
For the third shell M : 2(3)2 = 2 x 9 = 18
For the fourth shell N : 2(4)2 = 2 x 16 = 32
Valency : The number of valence electrons present in outer most shell of an atom is known as valency.
Example:
Electronic configuration of some elements and its valency:
(1) Sodium has 11 electrons,
Electronic configuration of sodium: 2, 8, 1
(2) Oxygen has 8 electrons,
Electronic configuration of Oxygen: 2, 6
Example: If there is 1 electron in outer most shell of atom of an element, then valency will be 1. If outer most shell has 2, 3 or 4 electron then valency will be 2, 3 or 4 respectively. But if outer most shell has 5, 6 or 7 electrons then valency will be find in such manner as follows.
When outer most shell has 5 electrons then valency will be 8 - 5 = 3
When outer most shell has 6 electrons then valency will be 8 - 6 = 2
When outer most shell has 7 electrons then valency will be 8 - 7 = 1
When outer most shell has 8 electrons then valency will be 8 - 8 = 0
Now, See this table:
| Name of Element | Symbol | No. of Atom | No. of protons | No. of Nutrons | No. of Electrons | Electronic configuration K L M N | Valency |
| Hydrogen | H | 1 | 1 | - | 1 | 1 | 1 |
| Helium | He | 2 | 2 | 2 | 2 | 2 | 0 |
| Lithium | Li | 3 | 3 | 3 | 3 | 2 1 | 1 |
| Berelium | Be | 4 | 4 | 4 | 4 | 2 2 | 2 |
| Boran | B | 5 | 5 | 5 | 5 | 2 3 | 3 |
| Carbon | C | 6 | 6 | 6 | 6 | 2 4 | 4 |
| Nitrogen | N | 7 | 7 | 7 | 7 | 2 5 | 3 |
| Oxygen | O | 8 | 8 | 8 | 8 | 2 6 | 2 |
| Flourine | F | 9 | 9 | 9 | 9 | 2 7 | 1 |
| Neon | Ne | 10 | 10 | 10 | 10 | 2 8 | 0 |
| Sodium | Na | 11 | 11 | 11 | 11 | 2 8 1 | 1 |
| Magnesium | Mg | 12 | 12 | 12 | 12 | 2 8 2 | 2 |
| Aluminium | Al | 13 | 13 | 13 | 13 | 2 8 3 | 3 |
| Silicon | Si | 14 | 14 | 14 | 14 | 2 8 4 | 4 |
| Phosphoras | P | 15 | 15 | 15 | 15 | 2 8 5 | 3, 5 |
| Sulphar | S | 16 | 16 | 16 | 16 | 2 8 6 | 2 |
| Chlorine | Cl | 17 | 17 | 17 | 17 | 2 8 7 | 1 |
| Argon | Ar | 18 | 18 | 18 | 18 | 2 8 8 | 0 |
Atomic Number: The total Number of protons present in the nucleus of an atom is known as atomic number.
Example - Let be the total number of protons in the nucleus of an atom is 8 then atomic number will be 8. Similarily if the total number of protons is 11 then atomic number that atom will be 11.
Atomic number = Number of protons
Atomic Mass: The sum of total number of protons and nutrons present in the nucleus of an atom is known as atomic Mass.
Example - If an atom has 4 protons and 5 nutrons in its nucleus then atomic mass will be 4 + 5 = 9.
Similarily if an atom has 7 protons and 7 nutrons the atomic mass will be 7 + 7 = 14.
Atomic Mass = No. of protons + No. of Electrons
Note: The number of protons in an atom is equal to the number of electron of an atom. The same number is its atomic number. The number of nutrons may be equal to the number of protons or may not be equal.
All Topics Chapter 4. Structure of The Atom
4. Structure of The Atom-Electronic Configuration And valency Science Class 9 In English-CBSE Notes
Hindi Medium Students/Teachers/Tutors:
All Chapters science Class 9
CBSE Notes for Class 9 science Chapter 4. Structure of The Atom – Electronic Configuration And valency
The CBSE Notes for Class 9 science Chapter 4. Structure of The Atom – Electronic Configuration And valency are prepared to help students understand every concept in a simple, clear, and well-organized manner. These notes are based on the latest CBSE syllabus and are suitable for regular classroom learning, homework, revision, and examination preparation. Every topic is explained using easy language so that students can learn important concepts without difficulty and develop a strong academic foundation.
Studying directly from the textbook is essential, but during revision students often need concise study material that highlights only the most important information. These chapter-wise notes provide exactly that. Instead of reading lengthy chapters repeatedly, students can quickly revise definitions, concepts, facts, examples, and important points in a short period of time. This approach saves valuable study time while improving understanding and retention.
Why Study Chapter 4. Structure of The Atom – Electronic Configuration And valency Using Our Notes?
Every chapter contains several important concepts that require careful understanding. Our notes present these concepts in a logical sequence so students can connect ideas easily. Difficult topics are simplified with easy explanations, making learning enjoyable for students of different learning abilities. Whether you are preparing for classroom discussions, assignments, periodic tests, or annual examinations, these notes provide a reliable source for effective revision.
- Prepared according to the latest CBSE curriculum.
- Simple and student-friendly explanations.
- Chapter-wise organized content for easy learning.
- Important concepts, definitions, and key points included.
- Useful for quick revision before examinations.
- Supports self-study and classroom learning.
- Helps improve conceptual understanding and confidence.
- Suitable for homework, assignments, and test preparation.
Benefits of Reading CBSE Notes Regularly
Consistent revision is one of the most effective ways to achieve academic success. Reading CBSE Notes for Class 9 science Chapter 4. Structure of The Atom – Electronic Configuration And valency regularly helps students remember important information for a longer period. Since the content is arranged systematically, students can identify important topics quickly and revise them whenever required.
These notes also help students improve answer-writing skills by presenting information in a structured format. Instead of memorizing lengthy paragraphs, students learn how to organize answers using important points and concepts. This not only improves writing quality but also increases confidence during examinations.
How to Use These Notes Effectively
To get the best results, students should first read the NCERT textbook carefully and understand the chapter. After completing the textbook, they should study these notes to reinforce important concepts. During revision, students can focus on highlighted definitions, important facts, and key ideas before solving textbook exercises and practice questions. This learning strategy improves both understanding and long-term memory.
Teachers and parents can also use these notes as a quick reference while helping students revise lessons or complete assignments. Since the content is concise and well-organized, it becomes easier to explain difficult topics within a limited amount of time.
Features of Our CBSE Notes
Every chapter on our platform is created with the objective of making learning easier for students. Our educational team regularly reviews and updates the content according to the latest CBSE guidelines so that students always receive reliable and accurate study material.
- Easy-to-understand chapter explanations.
- Important definitions and key concepts.
- Well-structured content for faster revision.
- Based on the latest CBSE syllabus.
- Helpful for school exams and annual examinations.
- Free online access on desktop and mobile devices.
Prepare Better with Chapter-wise CBSE Notes
Success in examinations depends on consistent practice and smart revision. These CBSE Notes for Class 9 science Chapter 4. Structure of The Atom – Electronic Configuration And valency are designed to reduce study pressure by presenting important information in a concise and meaningful way. Students can use them throughout the academic session for daily learning as well as last-minute revision before examinations.
Along with these notes, students are encouraged to solve NCERT textbook questions, practice important questions, and attempt sample papers regularly. Combining concept-based learning with regular practice helps improve problem-solving ability, analytical thinking, and overall academic performance. With disciplined study habits and quality learning resources, students can build confidence, strengthen their understanding of every chapter, and achieve excellent results in school examinations.
4. Structure of The Atom-Electronic Configuration And valency Science Class 9 In English-CBSE Notes Study Materials For Class 6 to 12
If you want to improve your academic performance, start studying with free CBSE notes for all classes. These notes are designed to make learning simple, clear, and effective for every student. Choose your class, explore the chapters, and begin your preparation with the latest cbse notes today.
