Class 10 Science Book Back Questions & Solutions

About Science

Medium ~18 h study

Science is indispensable for fostering a systematic comprehension of the natural world, driving intellectual curiosity, and cultivating crucial analytical capabilities. The Standard Ten curriculum bridges elementary observations with complex quantitative frameworks, making it a pivotal stepping stone for secondary education and competitive careers. By exploring how matter and energy interact, students develop critical thinking and scientific inquiry that empower them to address real-world challenges with evidence-based reasoning.

The syllabus is carefully designed to show how different scientific domains interconnect and build upon one another. Physical principles of mechanics, thermodynamics, and wave optics set the baseline for understanding electrical circuits and atomic structures. These concepts immediately enrich chemistry, where students analyze molecular bonds, solution concentrations, and chemical reaction pathways. Finally, these physical and chemical ideas come together in biology to explain physiological transport, genetics, and evolutionary processes that govern living organisms.

The board examination expects students to demonstrate holistic mastery of both theoretical principles and practical applications across the entire syllabus. Rather than relying on simple memorization, the assessment evaluates conceptual clarity, diagrammatic accuracy, and numerical problem-solving skills. Achieving success requires a clear understanding of experimental methodologies, chemical equations, and the biological processes discussed in the text, ensuring students can apply standard scientific concepts to unfamiliar scenarios.

What you'll learn

• Analyze physical systems using Newtonian concepts of force, inertia, and momentum.
• Explain the refraction, reflection, and scattering of light through various optical media.
• Evaluate the periodic properties of elements and their chemical reactivity trends across groups.
• Formulate organic compounds systematically using standard IUPAC nomenclature guidelines.
• Illustrate plant and animal anatomy, identifying major organ systems and their functions.
• Apply Mendel's laws of inheritance to solve genetic trait transmission problems.
• Synthesize evolutionary theories to describe the origin and gradual adaptation of species.
• Create animations and digital programs using basic block-based computer software.

Before you start

• Basic understanding of force, velocity, and motion from Class Nine physical science.
• Elementary knowledge of chemical symbols, elements, and simple molecular structures.
• Familiarity with plant and animal structures, and cell division basics from previous standards.

Science — the syllabus in depth

Core Thematic Areas of Standard Ten Science

Foundational Physics and Energy Systems

This segment explores the fundamental rules that govern the physical universe, establishing a bridge between abstract forces and visible phenomena. Students analyze Newtonian mechanics, focusing on the laws of motion, inertia, and universal gravitation to explain how forces dictate the behavior of bodies. The curriculum then moves into wave dynamics, exploring how light undergoes refraction and dispersion through different mediums, and how sound propagates through solid, liquid, and gas environments. Additionally, thermal physics introduces thermal equilibrium and ideal gas laws, while electricity covers charge circulation and circuits. Finally, nuclear physics explores atomic energy, distinguishing between natural and artificial radioactivity, fission, and fusion reactions, providing a robust overview of physical energy.

Atomic structures, Periodicity, and Solutions

This theme details the chemical composition of matter, starting with modern atomic theory and relative atomic masses. Students study how Avogadro's hypothesis relates equal volumes of gases to their molecular counts under identical temperature and pressure. The classification of elements through the periodic table is thoroughly explored, focusing on periodic trends like atomic radius, ionization energy, and electron affinity. Finally, the concepts of solutions, saturated and unsaturated concentrations, and the physical factors that influence solubility are discussed to explain everyday chemical mixtures.

Chemical Transformations and Organic Compounds

This unit investigates how chemical elements react, interact, and transform under various physiological and laboratory conditions. Students classify chemical reactions into fundamental categories such as combination, decomposition, displacement, and double displacement reactions. The vital role of pH value, indicators, and ionic equilibrium in biochemical systems is highly emphasized. This is followed by a rich introduction to organic chemistry, covering the unique catenation and tetravalent properties of carbon, successive members of homologous series, and the systematic naming of organic compounds using standard IUPAC nomenclature guidelines.

Plant Anatomy and Plant Physiology

This unit introduces plant biology, exploring the internal structural organization of plant tissues and their crucial physiological mechanisms. Students study tissue systems in roots, stems, and leaves, analyzing the transverse sections of monocot and dicot structures under microscopes. The study of photosynthesis explores both light-dependent and light-independent chemical reactions occurring in chloroplasts, while cellular respiration details the metabolic glycolysis, Krebs cycle, and electron transport chain pathways occurring within the mitochondria of plant cells to produce vital energy.

Animal Anatomy and Physiological Systems

Comparative animal biology focuses on the structural organization and parasitic adaptations of organisms like the leech and rabbit to highlight anatomical systems. Students study circulatory networks, comparing vascular transport in plants with blood circulation in mammals. This connects directly to human nervous system regulation, detailing the structural cerebrum and cerebellum brain functions, spinal cord reflex arcs, and endocrinology. Here, hormones released by specialized endocrine glands coordinate systemic bodily activities and maintain internal homeostatic balance in response to changing external stimuli.

Genetics, Evolution, and Environmental Science

The final theme explores hereditary transmission, evolutionary biology, biotechnology, lifestyle health, and ecological preservation. Gregor Mendel's monohybrid and dihybrid crosses demonstrate classical laws of trait inheritance across generations. Evolutionary theories explain how life originated and adapted through Darwinian natural selection and variation over billions of years. Modern biotechnology and breeding applications highlight agricultural yield enhancements, crop hybridization, and gene therapies. Finally, human health management addresses lifestyle diseases, paired with environmental conservation, highlighting waste reduction, renewable energy resources, and biodiversity protection to preserve the global biosphere.

How to study Science

To study Standard Ten Science effectively, begin with the core principles of Physics and Chemistry, as they establish the physical laws and chemical reactions needed for biological systems. Spend initial study hours on Newtonian motion, optics, and periodic trends, ensuring you practice numerical problems and chemical equations regularly. Next, transition to biological units, placing particular focus on cellular respiration, genetics, and nervous coordination, which require detailed diagrammatic review. Finally, address environmental science, health, and visual communication, which are highly conceptual and easier to digest.

Structure your weekly revision using this simple routine:

• Concept Mapping: Draw structural diagrams of physiological organs and review periodic trends to link topics.
• Problem Solving: Solve equations related to focal lengths, resistivity, and molecular masses.
• Active Recall: Utilize textbook review questions to test your understanding of mechanisms like reflex arcs and carbon bonding.

Dedicate the final weeks to writing mock tests and refining your diagram-labeling speed to ensure optimal time management during the board exam.

Common mistakes to avoid

• Confusing mass and weight: Remember that mass is the scalar quantity of matter contained in a body, whereas weight is the vector gravitational force exerted on it.
• Incorrectly applying Boyle's law: Ensure you recognize that pressure is inversely proportional to volume (PV = constant) only when temperature remains constant.
• Mislabeling refraction directions: Recall that light bends toward the normal when traveling from a rarer to denser medium, and away from it when transitioning to a rarer medium.
• Rounding off relative atomic masses: Keep values precise as stated in the textbook, such as using 35.5 a.m.u. for Chlorine, as rounding alters calculation accuracy.
• Writing incorrect IUPAC prefixes and suffixes: Verify the carbon chain length for correct prefixes and identify functional groups accurately to use proper suffixes like '-al' for aldehydes and '-ol' for alcohols.

Frequently asked questions

What is the difference between mass and weight?

Mass is the basic property of a body and is defined as the actual quantity of matter contained within it, measured in kilograms. In contrast, weight represents the gravitational force exerted on the body by the Earth and is measured in Newtons. While mass remains constant everywhere in the universe, weight varies depending on the local acceleration due to gravity.

What are the criteria for a planet to support life under astrobiology?

To support the existence of extra-terrestrial life, a planet must satisfy two key habitable zone criteria. First, the planet must possess the correct mass to retain a protective atmosphere. Second, it must maintain a stable orbit at a precise distance from its host star to allow temperatures suitable for liquid water.

How do you correct myopic and hypermetropic eye defects?

Myopia, or near-sightedness, occurs when light focuses in front of the retina and is corrected using a concave lens. Hypermetropia, or far-sightedness, occurs when light focuses behind the retina and is corrected using a convex lens. Presbyopia, another age-related eye defect, is corrected using bi-focal lenses.

What is the difference between nuclear fission and fusion?

Nuclear fission is the process where a heavier nucleus splits into smaller nuclei, releasing a large amount of energy, as seen when uranium is bombarded with neutrons. Nuclear fusion is the combining of lighter nuclei to form a heavier nucleus. Both processes release immense energy but fission is used in conventional reactors while fusion powers stars.

What is Avogadro's hypothesis in chemistry?

Avogadro's law states that equal volumes of all gases under similar conditions of temperature and pressure contain an equal number of molecules. This means the volume of any given gas is directly proportional to the number of gas molecules present in it when temperature and pressure are held constant.

How does the nervous system coordinate reflex actions?

A reflex action is an involuntary, instantaneous response to a stimulus. It operates through a pathway called a reflex arc. When a receptor cell detects a stimulus, like a prick on the hand, it sends an impulse through sensory neurons to the spinal cord. The spinal cord processes this and immediately sends motor signals to muscles to pull away.

What are the common lifestyle disorders and their causes?

Common lifestyle-associated disorders include obesity, cardiovascular diseases, and diabetes mellitus. Chronic obesity is heavily driven by high-calorie diet intake and physical inactivity. Diabetes includes insulin-dependent type-one and insulin-resistant type-two forms. These disorders are directly caused by improper dietary management, mental stress, lack of daily physical exercise, and other unhealthy lifestyle habits.

What is Boyle's law and how do you verify it?

Boyle's law states that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature. This can be verified experimentally using a syringe where decreasing the volume by pushing the piston increases the internal pressure, confirming that pressure times volume remains constant.

What is the role of pH in the human body?

The power of hydrogen or pH is vital for chemical balance in everyday life. In humans, all essential biochemical and enzymatic reactions take place within a narrow pH range of 7.0 to 7.8. Severe deviations from this physiological balance can disrupt metabolic systems and harm overall health.

What is the difference between a file and a folder?

A file is the actual output produced by a specific software application, containing data like notes, drawings, or spreadsheet information. A folder is a digital directory used to store, organize, and group these files in one place. You can create custom folders to arrange your work systematically in computer operating systems.