| Non-Rationalised Science NCERT Notes and Solutions (Class 6th to 10th) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6th | 7th | 8th | 9th | 10th | ||||||||||
| Non-Rationalised Science NCERT Notes and Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Non-Rationalised Science NCERT Notes and Solutions (Class 12th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
Class 9th Science NCERT Notes and Solutions (Non-Rationalised)
1. Matter In Our Surroundings
This chapter introduces the fundamental concept of matter as anything that has mass and occupies space. It explains that matter is composed of tiny, constantly moving particles. The chapter provides a detailed comparison of the three states of matter—solid, liquid, and gas—based on the varying forces of attraction and kinetic energy between their particles. It also explores the inter-conversion of these states through processes like melting, freezing, boiling (vaporisation), condensation, and sublimation. The concept of latent heat is introduced to explain the energy required for a change of state, and the cooling effect of evaporation is discussed with everyday examples.
2. Is Matter Around Us Pure?
This chapter classifies matter based on its chemical composition into pure substances (elements and compounds) and mixtures. Mixtures are further categorized as homogeneous (with a uniform composition, like a salt solution) and heterogeneous (with a non-uniform composition, like sand in water). The chapter details various physical techniques for separating the components of a mixture, such as filtration, evaporation, distillation, and chromatography, chosen based on the properties of the components. It also provides a clear distinction between true solutions, suspensions, and colloidal solutions based on their particle size, stability, and the Tyndall effect.
3. Atoms And Molecules
This foundational chemistry chapter introduces the building blocks of matter: atoms and molecules. It is built upon the two fundamental Laws of Chemical Combination: the Law of Conservation of Mass and the Law of Constant Proportions. The chapter explains the key postulates of Dalton's Atomic Theory, which provided a scientific basis for understanding chemical reactions. It introduces crucial quantitative concepts like atomic mass, molecular mass, and the mole concept. The mole is defined as a quantity containing Avogadro's number ($\textsf{N}_\textsf{A} = 6.022 \times 10^{23}$) of particles, serving as a bridge between the mass of a substance and the number of its constituent particles.
4. Structure Of The Atom
This chapter delves into the internal structure of the atom, revealing that it is composed of even smaller subatomic particles. It traces the historical development of atomic models, from J.J. Thomson's "plum pudding" model following the discovery of the electron, to Rutherford's nuclear model based on his gold foil experiment, which established the existence of a dense, positive nucleus. The chapter also discusses Bohr's model, which introduced the idea of discrete energy shells. It defines atomic number (Z) as the number of protons and mass number (A) as the total number of protons and neutrons. The concepts of isotopes and isobars are also explained.
5. The Fundamental Unit Of Life
This foundational biology chapter establishes the cell as the basic structural and functional unit of all living organisms. It introduces the discovery of the cell and the formulation of the Cell Theory. The chapter provides a detailed overview of the components of a cell, differentiating between prokaryotic and eukaryotic cells, as well as plant and animal cells. Key structures discussed include the selectively permeable cell membrane, the rigid cell wall (in plants), the control centre or nucleus containing genetic material, and the jelly-like cytoplasm. It also explains the functions of various specialized cell organelles like mitochondria (powerhouse), endoplasmic reticulum, Golgi apparatus, and plastids.
6. Tissues
In multicellular organisms, cells group together to form tissues, which are specialized to perform specific functions, illustrating a division of labour. This chapter explores the different types of tissues in plants and animals. Plant tissues are classified into meristematic tissues (responsible for growth) and permanent tissues. Permanent tissues include simple tissues (like parenchyma) and complex tissues like xylem (for water conduction) and phloem (for food transport). Animal tissues are categorised into four main types: epithelial tissue (for protection), connective tissue (for support, e.g., blood and bone), muscular tissue (for movement), and nervous tissue (for communication).
7. Diversity In Living Organisms
This chapter explores the immense variety of life on Earth and the scientific basis for its classification. It introduces the concept of a classification hierarchy, from species to kingdom. The chapter focuses on the Five Kingdom classification system proposed by Whittaker, which groups organisms into Monera, Protista, Fungi, Plantae, and Animalia based on characteristics like cell structure and mode of nutrition. It provides a brief overview of the major subdivisions within the Plant Kingdom (from Algae to Angiosperms) and the Animal Kingdom (from Porifera to Chordata), highlighting key evolutionary advancements and distinguishing features of each group.
8. Motion
This physics chapter provides a formal description of motion. It distinguishes between scalar quantities like distance and speed, and vector quantities like displacement and velocity. The concept of acceleration is introduced as the rate of change of velocity. The chapter emphasizes the use of graphs, particularly distance-time and velocity-time graphs, as powerful tools to analyze and represent an object's motion. It culminates in the derivation and application of the three fundamental equations of motion for uniformly accelerated linear motion: $\textsf{v = u + at}$, $\textsf{s = ut} + \frac{1}{2}\textsf{at}^2$, and $\textsf{v}^2 = \textsf{u}^2 + \textsf{2as}$.
9. Force And Laws Of Motion
This chapter delves into dynamics, exploring the cause of motion: force. It establishes the bedrock principles of classical mechanics through Newton's three laws of motion. The First Law defines inertia, the resistance to change in motion. The Second Law provides the quantitative relationship between force, mass, and acceleration ($\textsf{F = ma}$). The Third Law states that for every action, there is an equal and opposite reaction. The important concept of linear momentum ($\textsf{p = mv}$) is introduced, leading to the fundamental principle of the Conservation of Momentum, which governs interactions like collisions.
10. Gravitation
This chapter explores the universal force of attraction that governs everything from falling apples to orbiting planets. It introduces Newton's Universal Law of Gravitation ($\textsf{F} = \textsf{G}\frac{\textsf{m}_1\textsf{m}_2}{\textsf{r}^2}$). It explains the concept of free fall and defines the acceleration due to gravity ($\textsf{g}$). A key distinction is made between mass (the amount of matter, which is constant) and weight (the force of gravity, which varies). The chapter also explores pressure in fluids, introducing the concept of buoyancy and Archimedes' principle, which explains why objects float or sink.
11. Work And Energy
This chapter introduces the scientific definitions of work, energy, and power. Work is defined as being done only when a force produces a displacement in its direction ($\textsf{W} = \textsf{F} \times \textsf{s}$). Energy is introduced as the capacity to do work. The chapter focuses on two main forms of mechanical energy: kinetic energy ($\textsf{KE} = \frac{1}{2}\textsf{mv}^2$), the energy of motion, and potential energy, the energy stored due to position. It establishes the fundamental Law of Conservation of Energy, stating that energy can only be transformed from one form to another. Finally, power is defined as the rate at which work is done.
12. Sound
This chapter explores the physics of sound, defining it as a mechanical, longitudinal wave that requires a medium for its propagation. It explains how sound is produced by vibrating objects, creating a series of compressions and rarefactions. Key characteristics of sound waves are defined, including wavelength, frequency (which determines pitch), and amplitude (which determines loudness). The chapter discusses the reflection of sound, which leads to phenomena like echoes, and covers the range of human hearing (approximately 20 Hz to 20,000 Hz), introducing the concepts of infrasound and ultrasound and their applications.
13. Why Do We Fall Ill?
This chapter introduces the concepts of health and disease from a biological and social perspective. It defines health as a state of complete physical, mental, and social well-being. It distinguishes between acute and chronic diseases and classifies them based on their causes as infectious diseases (caused by pathogens like viruses and bacteria) and non-infectious diseases (caused by factors like genetics or lifestyle). The chapter discusses the different means by which infectious diseases spread and emphasizes the principles of prevention, including sanitation, immunization (vaccination), and maintaining a healthy community environment.
14. Natural Resources
This chapter focuses on the vital resources that the Earth provides, which are essential for sustaining life. It discusses the "spheres" of the Earth: the atmosphere (air), the hydrosphere (water), and the lithosphere (land and soil). A major focus is on the biogeochemical cycles, which describe the movement of essential elements like water, nitrogen, carbon, and oxygen through the biotic and abiotic components of the biosphere. The chapter also addresses critical environmental issues like air pollution (and the hole in the ozone layer), water pollution, and soil erosion, highlighting the impact of human activities on these precious resources.
15. Improvement In Food Resources
This chapter addresses the challenge of providing sufficient and nutritious food for a growing population. It discusses scientific approaches to enhance food production from both plants and animals. For crops, it covers three main areas: crop variety improvement (through techniques like hybridisation), crop production management (nutrient management, irrigation, and cropping patterns), and crop protection management (controlling weeds, pests, and diseases). It also delves into animal husbandry, discussing scientific management practices for cattle farming (for milk and draught), poultry farming, and fish farming (pisciculture), all with a focus on achieving higher yields sustainably.