| Latest Science NCERT Notes and Solutions (Class 6th to 10th) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 6th | 7th | 8th | 9th | 10th | ||||||||||
| Latest Science NCERT Notes and Solutions (Class 11th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
| Latest Science NCERT Notes and Solutions (Class 12th) | ||||||||||||||
| Physics | Chemistry | Biology | ||||||||||||
Latest Class 7th Science NCERT (Curiosity) Concepts & Solutions
1. The Ever-Evolving World of Science
Science is not a collection of unchanging facts; it is a dynamic and continuously evolving process of inquiry. This chapter highlights how our scientific understanding progresses through new discoveries, rigorous experimentation, and the courage to question existing knowledge. It illustrates that science is a journey of constant exploration and refinement, where theories are tested, modified, or even replaced with better ones as new evidence emerges. This evolution of science is what drives technological innovation and progress in all aspects of our lives, from medicine to communication.
2. Exploring Substances: Acidic, Basic, and Neutral
Substances around us can be classified based on their chemical nature as acidic, basic, or neutral. This chapter introduces the concepts of acids (typically sour, like lemon juice) and bases (typically bitter and soapy to touch, like baking soda solution). It explains that touching or tasting unknown chemicals is dangerous. Instead, we use special substances called indicators to test them. You will learn about natural indicators like litmus and turmeric, and how they change colour to identify acids and bases. The chapter also introduces the concept of a neutralisation reaction, where an acid and a base react to form salt and water, cancelling out each other's effects.
3. Electricity: Circuits and their Components
Electricity, the flow of electric charge, powers much of our modern world. This chapter introduces the basics of electric current and the concept of a simple electric circuit, which is a closed path for electricity to flow. You will learn to identify and draw symbols for essential components like a cell (source of electricity), a bulb (the load), wires (conductors), and a switch (to open or close the circuit). The chapter explains the difference between an open circuit (incomplete path, no current flows) and a closed circuit (complete path, current flows). It also briefly touches upon the heating effect of electric current, which is why a bulb's filament glows.
4. The World of Metals and Non-metals
Materials can broadly be categorised as metals or non-metals, each having distinct properties. This chapter explores the physical characteristics that differentiate them. Metals (e.g., iron, copper, gold) are typically lustrous (shiny), hard, malleable (can be beaten into thin sheets), ductile (can be drawn into wires), sonorous (make a ringing sound), and are good conductors of heat and electricity. In contrast, non-metals (e.g., carbon, sulfur, oxygen) are usually dull, brittle, and are poor conductors (insulators). Understanding these fundamental differences helps us appreciate their varied and specific uses in our daily lives.
5. Changes Around Us: Physical and Chemical
The world around us is in a constant state of flux. These changes can be broadly classified as physical or chemical. This chapter teaches you to differentiate between them. A physical change is a change in the physical properties like shape, size, or state of a substance, but no new substance is formed. These changes, like melting of ice or tearing paper, are often reversible. A chemical change, however, results in the formation of one or more entirely new substances with different properties. Examples include the rusting of iron or the burning of wood. Chemical changes are generally irreversible.
6. Adolescence: A Stage of Growth and Change
Adolescence is a significant transitional phase in life, marking the journey from childhood to adulthood. This chapter explores the profound physical, mental, and emotional changes that occur during this period, a process known as puberty. It discusses the role of hormones in triggering a sudden increase in height (growth spurt) and the development of secondary sexual characteristics, such as the growth of facial hair in boys and the development of breasts in girls. The chapter also addresses the importance of personal hygiene, balanced nutrition, and managing the emotional adjustments associated with this critical stage of life.
7. Heat Transfer in Nature
Heat is a form of energy that naturally flows from a region of higher temperature to a region of lower temperature. This chapter delves into the three main modes of heat transfer. Conduction is the transfer of heat through direct contact, mainly in solids like a hot metal rod. Convection is the transfer of heat through the movement of fluids (liquids or gases), which explains phenomena like the boiling of water and the formation of sea and land breezes. Radiation is the transfer of heat through electromagnetic waves, which does not require any medium. This is how we feel the heat from the Sun or a nearby fire.
8. Measurement of Time and Motion
Quantifying time and motion is essential for describing and understanding the physical world. This chapter revisits time measurement using devices like clocks and pendulums. It then introduces the concept of speed, which is defined as the distance covered by an object in a unit of time ($\textsf{Speed} = \frac{\textsf{Distance}}{\textsf{Time}}$). You will learn to distinguish between uniform motion, where an object moves at a constant speed in a straight line, and non-uniform motion, where the speed of the object changes. Simple calculations involving speed, distance, and time are also explained to help describe how things move.
9. Life Processes in Animals
Animals, including humans, perform various essential life processes to survive, grow, and continue their species. This chapter explores these key biological functions. It covers nutrition (how animals obtain and utilize food), respiration (the process of breathing to release energy from food), circulation (the transport of nutrients, oxygen, and wastes through the blood), and excretion (the removal of metabolic waste products from the body). A basic introduction to reproduction, the process of creating new life, is also discussed. Understanding these interconnected processes provides insight into the complex systems that sustain animal life.
10. Life Processes in Plants
Plants are vital autotrophs that form the base of most food chains on Earth. This chapter focuses on the unique life processes in plants. A major focus is on photosynthesis, the remarkable process where plants use sunlight, water, and carbon dioxide to produce their own food (glucose) and release oxygen. It also covers transportation of water and minerals through the xylem and food through the phloem. Other key processes discussed include respiration (using food for energy), transpiration (the loss of water vapour from leaves), and reproduction through flowers, leading to pollination and seed formation.
11. Light: Shadows and Reflections
Light is a form of energy that enables our sense of sight and travels in straight lines, a property known as the rectilinear propagation of light. This chapter explores key phenomena related to light. You will learn how shadows are formed when an opaque object blocks the path of light. The chapter then delves into reflection, which is the bouncing back of light from a surface. It introduces the laws of reflection and explains how plane mirrors form images that are virtual (cannot be formed on a screen), erect, and laterally inverted (left appears right).
12. Earth, Moon, and the Sun
Our immediate cosmic neighbourhood is dominated by the dynamic relationship between the Earth, its Moon, and our star, the Sun. This chapter introduces these celestial bodies. You'll learn about the Earth's rotation on its axis, which causes the cycle of day and night, and its revolution around the Sun, which, along with its tilted axis, results in the changing of seasons. It explores the Moon as Earth's natural satellite and explains how its revolution around the Earth causes the different phases of the moon we observe. The Sun is presented as the ultimate source of light and energy for all life on Earth.