CBSE Class 10 · Science
Prepared by: Muhammad Jaisal · Learnify Academy, Bahrain
Quick Revision Notes
All Chapters
13 chapters per CBSE 2025-26 syllabus. Equations rendered with MathJax.
13
Chapters
80
Theory Marks
20
Practical
3h
Exam Duration
📋 Exam Pattern & Strategy
80 marks theory + 20 practical. Removed chapters: 5, 14, 16 (Periodic Classification, Sources of Energy, Natural Resources). Focus on NCERT.
20 MCQs × 1
6 SA × 2
7 SA × 3
3 LA × 5
📚
⚡
Exam Tip
Attempt MCQs first, then short answers, then long answers. Always balance equations with state symbols (s, l, g, aq).
1
Chemical Reactions and Equations
Balancing · Types · Exo/Endothermic · Redox · Corrosion
Key Points
Chemical equations must be balanced – atoms conserved. State symbols: (s), (l), (g), (aq).
Law of Conservation of Mass: total mass of reactants = total mass of products.
Oxidation = gain of O / loss of H. Reduction = loss of O / gain of H. Redox reactions: both occur.
Rancidity: oxidation of fats in food – prevented by antioxidants, airtight containers, nitrogen flushing.
Reaction Types
Combination
\( \text{CaO}(s) + \text{H}_2\text{O}(l) \rightarrow \text{Ca(OH)}_2(aq) + \text{Heat} \)
Endothermic Decomposition
\( 2\text{FeSO}_4(s) \xrightarrow{\Delta} \text{Fe}_2\text{O}_3(s) + \text{SO}_2(g) + \text{SO}_3(g) \)
Displacement
\( \text{Zn}(s) + \text{CuSO}_4(aq) \rightarrow \text{ZnSO}_4(aq) + \text{Cu}(s) \)
Double Displacement (Precipitation)
\( \text{KCl}(aq) + \text{AgNO}_3(aq) \rightarrow \text{AgCl}(s)\downarrow + \text{KNO}_3(aq) \)
\( \sum m_{\text{reactants}} = \sum m_{\text{products}} \)Law of Conservation of Mass
2
Acids, Bases and Salts
pH scale · Indicators · Important salts · Chlor-alkali
Key Points
Arrhenius: Acid → H⁺ in water; Base → OH⁻ in water. pH < 7 acidic, pH = 7 neutral, pH > 7 basic.
Indicators: Blue litmus → red in acid; red litmus → blue in base. Phenolphthalein: colourless in acid, pink in base.
Chlor-alkali process: \( 2\text{NaCl}(aq) + 2\text{H}_2\text{O}(l) \xrightarrow{\text{electrolysis}} 2\text{NaOH}(aq) + \text{Cl}_2(g) + \text{H}_2(g) \). Products: NaOH, Cl₂, H₂.
Key salts: NaHCO₃ (baking soda), Na₂CO₃·10H₂O (washing soda), CaOCl₂ (bleaching powder), CaSO₄·½H₂O (Plaster of Paris).
Acid + Base → Salt + Water
\( \text{NaOH}(aq) + \text{HCl}(aq) \rightarrow \text{NaCl}(aq) + \text{H}_2\text{O}(l) \)
Baking Soda Heated
\( 2\text{NaHCO}_3(s) \xrightarrow{\Delta} \text{Na}_2\text{CO}_3(s) + \text{H}_2\text{O}(g) + \text{CO}_2(g)\uparrow \)
3
Metals and Non-metals
Reactivity series · Extraction · Corrosion · Thermite
Key Points
Metals: lustrous, malleable, ductile, good conductors, form basic oxides. Non-metals: dull, brittle, poor conductors, form acidic oxides.
Reactivity series (most to least): K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au.
Extraction: Highly reactive → electrolytic reduction; moderately reactive → carbon reduction; less reactive → native state.
Thermite reaction: \( \text{Fe}_2\text{O}_3(s) + 2\text{Al}(s) \rightarrow \text{Al}_2\text{O}_3(s) + 2\text{Fe}(l) + \text{Heat} \) – used for welding.
4
Carbon and its Compounds
Catenation · Homologous series · Functional groups · Soaps & detergents
Key Points
Catenation: carbon's ability to bond with itself, forming long chains. Tetravalency: forms 4 covalent bonds.
Homologous series: compounds with same functional group, differing by –CH₂–. Alkanes: CₙH₂ₙ₊₂; Alkenes: CₙH₂ₙ; Alkynes: CₙH₂ₙ₋₂.
Esterification: \( \text{C}_2\text{H}_5\text{OH} + \text{CH}_3\text{COOH} \rightleftharpoons \text{CH}_3\text{COOC}_2\text{H}_5 + \text{H}_2\text{O} \). Saponification: fat/oil + NaOH → soap + glycerol.
Substitution (UV light)
\( \text{CH}_4(g) + \text{Cl}_2(g) \xrightarrow{h\nu} \text{CH}_3\text{Cl}(g) + \text{HCl}(g) \)
Addition (Hydrogenation)
\( \text{CH}_2{=}\text{CH}_2(g) + \text{H}_2(g) \xrightarrow{\text{Ni}} \text{CH}_3\text{CH}_3(g) \)
6
Life Processes
Photosynthesis · Respiration · Nutrition · Circulation · Excretion
Key Equations
Photosynthesis
\( 6\text{CO}_2 + 6\text{H}_2\text{O} \xrightarrow{\text{Sunlight + Chlorophyll}} \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \)
Aerobic Respiration
\( \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy (ATP)} \)
Anaerobic in Yeast
\( \text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2 + \text{Energy} \)
Xylem: transports water and minerals upward. Phloem: transports food (sucrose) bidirectionally.
Nephron: ultrafiltration in Bowman's capsule → selective reabsorption → urine formation.
7
Control and Coordination
Reflex arc · Nervous system · Hormones · Plant hormones
Reflex arc: Stimulus → Receptor → Sensory neuron → Relay neuron (spinal cord) → Motor neuron → Effector → Response (does NOT involve brain).
Brain: Cerebrum (thinking, memory), Cerebellum (balance), Medulla oblongata (involuntary actions).
Hormones: Insulin (lowers blood glucose), Glucagon (raises blood glucose), Adrenaline (fight or flight), Thyroxine (regulates metabolism).
Plant hormones: Auxins (phototropism), Gibberellins (stem elongation), Cytokinins (cell division), Abscisic acid (stomatal closure).
8
How do Organisms Reproduce?
Asexual · Sexual in plants · Sexual in humans · Contraception
Asexual: binary fission (amoeba), budding (yeast), spore formation (rhizopus), regeneration (planaria), vegetative propagation (potato).
Sexual reproduction in plants: flower → pollination → fertilization (pollen tube) → zygote → seed → fruit.
Male: testes produce sperm; Female: ovaries release ovum. Fertilization in fallopian tube → zygote → embryo implants in uterus.
Contraception: barrier (condom), chemical (pills), IUD (copper-T), surgical (vasectomy/tubectomy).
9
Heredity and Evolution
Mendel's laws · Punnett squares · Sex determination · Natural selection
Mendel's monohybrid cross F₂ ratio: 3 dominant : 1 recessive. Dihybrid cross F₂ ratio: 9:3:3:1.
Sex determination in humans: Female XX, Male XY. Father determines sex of child (X → girl, Y → boy).
Homologous structures (same origin, different functions) indicate common ancestry. Analogous structures (different origin, similar function) indicate convergent evolution.
Natural selection (Darwin): favourable variations increase survival and reproduction → gradual evolution.
10
Light – Reflection and Refraction
Mirror & lens formula · Magnification · Snell's law
Mirror: \( \frac{1}{f} = \frac{1}{v} + \frac{1}{u} \)\( m = -\frac{v}{u} \)
Lens: \( \frac{1}{f} = \frac{1}{v} - \frac{1}{u} \)\( m = \frac{v}{u} \)
Snell's Law: \( n_1 \sin\theta_1 = n_2 \sin\theta_2 \)Refractive index \( n = \frac{c}{v} \)
Lens Power: \( P = \frac{1}{f(\text{m})} \) (Diopters)
Concave mirror: real, inverted images (object beyond F); virtual, erect, magnified (object between F and P).
Convex lens: converges light; concave lens diverges light.
Dispersion: white light splits into VIBGYOR by prism – red deviates least, violet most.
11
Human Eye and the Colourful World
Eye structure · Vision defects · Atmospheric refraction · Tyndall effect
Myopia (short-sight): concave lens correction. Hypermetropia (long-sight): convex lens correction.
Power of accommodation: ability of eye lens to change focal length to see near/far objects.
Blue sky: Rayleigh scattering ∝ 1/λ⁴ – blue light scattered most. Red sunrise/sunset: longer path, blue scattered away.
Stars twinkle due to atmospheric refraction; planets do not twinkle (extended sources).
12
Electricity
Ohm's law · Resistance · Series & parallel · Power · Joule's law
\( V = IR \)Ohm's Law
\( R = \rho \frac{l}{A} \)Resistivity (ρ in Ω·m)
\( P = VI = I^2R = \frac{V^2}{R} \)Electric power
\( H = I^2Rt \)Joule's law of heating
Series: \( R_s = R_1 + R_2 + \cdots \)Parallel: \( \frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2} + \cdots \)
13
Magnetic Effects of Electric Current
Oersted · Fleming's rules · Motor · Generator · Domestic circuits
Fleming's Left-Hand Rule (motor): Forefinger = Field, Middle finger = Current, Thumb = Motion/Force.
Fleming's Right-Hand Rule (generator): Forefinger = Field, Thumb = Motion, Middle finger = Induced Current.
Electric motor: converts electrical → mechanical energy. Generator: converts mechanical → electrical energy.
Domestic circuits: Live (220 V), Neutral (0 V), Earth (safety). Appliances connected in parallel.
\( F = BIl \)Force on current-carrying conductor
15
Our Environment
Ecosystem · Food chains · 10% energy rule · Biomagnification · Ozone
10% energy rule: only ~10% of energy transfers from one trophic level to the next; 90% lost as heat.
Biomagnification: non-biodegradable chemicals (DDT) increase in concentration at higher trophic levels.
Ozone layer (stratosphere) absorbs harmful UV radiation. CFCs cause ozone depletion → ozone hole.
3 R's: Reduce, Reuse, Recycle – sustainable waste management.
📘 Learnify Academy — CBSE Tuition in Bahrain
Experienced teachers · Small groups · Weekly assessments · Exam-oriented preparation
Enroll for CBSE Tuition →Quick Revision Tips & Exam Strategy
Last-minute pointers to maximise your score
📋
Formulas Cheat Sheet
Mirror: \(1/f=1/v+1/u\), Lens: \(1/f=1/v-1/u\), Ohm's \(V=IR\), Power \(P=VI\).
⚡
Attempt Order
MCQs first → 2-mark → 3-mark → 5-mark with diagrams.
✍️
Balance Equations
Always include state symbols. Double-check coefficients.
🖊️
Label Diagrams
Human eye, nephron, ray diagrams – labels earn full marks.
🔍
Mirror vs Lens
Mirror: \(m=-v/u\); Lens: \(m=v/u\). Formula signs differ.
🎯
High-Yield Topics
Chemical equations, Life processes, Electricity numericals, Reflection, Heredity.
CBSE Class 10 · Science
Prepared by: Muhammad Jaisal · Learnify Academy, Bahrain
Quick Revision Notes
All Chapters
13 chapters per CBSE 2025-26 syllabus. Equations rendered with MathJax.
13
Chapters
80
Theory Marks
20
Practical
3h
Exam Duration
📋 Exam Pattern & Strategy
80 marks theory + 20 practical. Removed chapters: 5, 14, 16 (Periodic Classification, Sources of Energy, Natural Resources). Focus on NCERT.
20 MCQs × 1
6 SA × 2
7 SA × 3
3 LA × 5
📚
⚡
Exam Tip
Attempt MCQs first, then short answers, then long answers. Always balance equations with state symbols (s, l, g, aq).
1
Chemical Reactions and Equations
Balancing · Types · Exo/Endothermic · Redox · Corrosion
Key Points
Chemical equations must be balanced – atoms conserved. State symbols: (s), (l), (g), (aq).
Law of Conservation of Mass: total mass of reactants = total mass of products.
Oxidation = gain of O / loss of H. Reduction = loss of O / gain of H. Redox reactions: both occur.
Rancidity: oxidation of fats in food – prevented by antioxidants, airtight containers, nitrogen flushing.
Reaction Types
Combination
\( \text{CaO}(s) + \text{H}_2\text{O}(l) \rightarrow \text{Ca(OH)}_2(aq) + \text{Heat} \)
Endothermic Decomposition
\( 2\text{FeSO}_4(s) \xrightarrow{\Delta} \text{Fe}_2\text{O}_3(s) + \text{SO}_2(g) + \text{SO}_3(g) \)
Displacement
\( \text{Zn}(s) + \text{CuSO}_4(aq) \rightarrow \text{ZnSO}_4(aq) + \text{Cu}(s) \)
Double Displacement (Precipitation)
\( \text{KCl}(aq) + \text{AgNO}_3(aq) \rightarrow \text{AgCl}(s)\downarrow + \text{KNO}_3(aq) \)
\( \sum m_{\text{reactants}} = \sum m_{\text{products}} \)Law of Conservation of Mass
2
Acids, Bases and Salts
pH scale · Indicators · Important salts · Chlor-alkali
Key Points
Arrhenius: Acid → H⁺ in water; Base → OH⁻ in water. pH < 7 acidic, pH = 7 neutral, pH > 7 basic.
Indicators: Blue litmus → red in acid; red litmus → blue in base. Phenolphthalein: colourless in acid, pink in base.
Chlor-alkali process: \( 2\text{NaCl}(aq) + 2\text{H}_2\text{O}(l) \xrightarrow{\text{electrolysis}} 2\text{NaOH}(aq) + \text{Cl}_2(g) + \text{H}_2(g) \). Products: NaOH, Cl₂, H₂.
Key salts: NaHCO₃ (baking soda), Na₂CO₃·10H₂O (washing soda), CaOCl₂ (bleaching powder), CaSO₄·½H₂O (Plaster of Paris).
Acid + Base → Salt + Water
\( \text{NaOH}(aq) + \text{HCl}(aq) \rightarrow \text{NaCl}(aq) + \text{H}_2\text{O}(l) \)
Baking Soda Heated
\( 2\text{NaHCO}_3(s) \xrightarrow{\Delta} \text{Na}_2\text{CO}_3(s) + \text{H}_2\text{O}(g) + \text{CO}_2(g)\uparrow \)
3
Metals and Non-metals
Reactivity series · Extraction · Corrosion · Thermite
Key Points
Metals: lustrous, malleable, ductile, good conductors, form basic oxides. Non-metals: dull, brittle, poor conductors, form acidic oxides.
Reactivity series (most to least): K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Ag > Au.
Extraction: Highly reactive → electrolytic reduction; moderately reactive → carbon reduction; less reactive → native state.
Thermite reaction: \( \text{Fe}_2\text{O}_3(s) + 2\text{Al}(s) \rightarrow \text{Al}_2\text{O}_3(s) + 2\text{Fe}(l) + \text{Heat} \) – used for welding.
4
Carbon and its Compounds
Catenation · Homologous series · Functional groups · Soaps & detergents
Key Points
Catenation: carbon's ability to bond with itself, forming long chains. Tetravalency: forms 4 covalent bonds.
Homologous series: compounds with same functional group, differing by –CH₂–. Alkanes: CₙH₂ₙ₊₂; Alkenes: CₙH₂ₙ; Alkynes: CₙH₂ₙ₋₂.
Esterification: \( \text{C}_2\text{H}_5\text{OH} + \text{CH}_3\text{COOH} \rightleftharpoons \text{CH}_3\text{COOC}_2\text{H}_5 + \text{H}_2\text{O} \). Saponification: fat/oil + NaOH → soap + glycerol.
Substitution (UV light)
\( \text{CH}_4(g) + \text{Cl}_2(g) \xrightarrow{h\nu} \text{CH}_3\text{Cl}(g) + \text{HCl}(g) \)
Addition (Hydrogenation)
\( \text{CH}_2{=}\text{CH}_2(g) + \text{H}_2(g) \xrightarrow{\text{Ni}} \text{CH}_3\text{CH}_3(g) \)
6
Life Processes
Photosynthesis · Respiration · Nutrition · Circulation · Excretion
Key Equations
Photosynthesis
\( 6\text{CO}_2 + 6\text{H}_2\text{O} \xrightarrow{\text{Sunlight + Chlorophyll}} \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \)
Aerobic Respiration
\( \text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{Energy (ATP)} \)
Anaerobic in Yeast
\( \text{C}_6\text{H}_{12}\text{O}_6 \rightarrow 2\text{C}_2\text{H}_5\text{OH} + 2\text{CO}_2 + \text{Energy} \)
Xylem: transports water and minerals upward. Phloem: transports food (sucrose) bidirectionally.
Nephron: ultrafiltration in Bowman's capsule → selective reabsorption → urine formation.
7
Control and Coordination
Reflex arc · Nervous system · Hormones · Plant hormones
Reflex arc: Stimulus → Receptor → Sensory neuron → Relay neuron (spinal cord) → Motor neuron → Effector → Response (does NOT involve brain).
Brain: Cerebrum (thinking, memory), Cerebellum (balance), Medulla oblongata (involuntary actions).
Hormones: Insulin (lowers blood glucose), Glucagon (raises blood glucose), Adrenaline (fight or flight), Thyroxine (regulates metabolism).
Plant hormones: Auxins (phototropism), Gibberellins (stem elongation), Cytokinins (cell division), Abscisic acid (stomatal closure).
8
How do Organisms Reproduce?
Asexual · Sexual in plants · Sexual in humans · Contraception
Asexual: binary fission (amoeba), budding (yeast), spore formation (rhizopus), regeneration (planaria), vegetative propagation (potato).
Sexual reproduction in plants: flower → pollination → fertilization (pollen tube) → zygote → seed → fruit.
Male: testes produce sperm; Female: ovaries release ovum. Fertilization in fallopian tube → zygote → embryo implants in uterus.
Contraception: barrier (condom), chemical (pills), IUD (copper-T), surgical (vasectomy/tubectomy).
9
Heredity and Evolution
Mendel's laws · Punnett squares · Sex determination · Natural selection
Mendel's monohybrid cross F₂ ratio: 3 dominant : 1 recessive. Dihybrid cross F₂ ratio: 9:3:3:1.
Sex determination in humans: Female XX, Male XY. Father determines sex of child (X → girl, Y → boy).
Homologous structures (same origin, different functions) indicate common ancestry. Analogous structures (different origin, similar function) indicate convergent evolution.
Natural selection (Darwin): favourable variations increase survival and reproduction → gradual evolution.
10
Light – Reflection and Refraction
Mirror & lens formula · Magnification · Snell's law
Mirror: \( \frac{1}{f} = \frac{1}{v} + \frac{1}{u} \)\( m = -\frac{v}{u} \)
Lens: \( \frac{1}{f} = \frac{1}{v} - \frac{1}{u} \)\( m = \frac{v}{u} \)
Snell's Law: \( n_1 \sin\theta_1 = n_2 \sin\theta_2 \)Refractive index \( n = \frac{c}{v} \)
Lens Power: \( P = \frac{1}{f(\text{m})} \) (Diopters)
Concave mirror: real, inverted images (object beyond F); virtual, erect, magnified (object between F and P).
Convex lens: converges light; concave lens diverges light.
Dispersion: white light splits into VIBGYOR by prism – red deviates least, violet most.
11
Human Eye and the Colourful World
Eye structure · Vision defects · Atmospheric refraction · Tyndall effect
Myopia (short-sight): concave lens correction. Hypermetropia (long-sight): convex lens correction.
Power of accommodation: ability of eye lens to change focal length to see near/far objects.
Blue sky: Rayleigh scattering ∝ 1/λ⁴ – blue light scattered most. Red sunrise/sunset: longer path, blue scattered away.
Stars twinkle due to atmospheric refraction; planets do not twinkle (extended sources).
12
Electricity
Ohm's law · Resistance · Series & parallel · Power · Joule's law
\( V = IR \)Ohm's Law
\( R = \rho \frac{l}{A} \)Resistivity (ρ in Ω·m)
\( P = VI = I^2R = \frac{V^2}{R} \)Electric power
\( H = I^2Rt \)Joule's law of heating
Series: \( R_s = R_1 + R_2 + \cdots \)Parallel: \( \frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2} + \cdots \)
13
Magnetic Effects of Electric Current
Oersted · Fleming's rules · Motor · Generator · Domestic circuits
Fleming's Left-Hand Rule (motor): Forefinger = Field, Middle finger = Current, Thumb = Motion/Force.
Fleming's Right-Hand Rule (generator): Forefinger = Field, Thumb = Motion, Middle finger = Induced Current.
Electric motor: converts electrical → mechanical energy. Generator: converts mechanical → electrical energy.
Domestic circuits: Live (220 V), Neutral (0 V), Earth (safety). Appliances connected in parallel.
\( F = BIl \)Force on current-carrying conductor
15
Our Environment
Ecosystem · Food chains · 10% energy rule · Biomagnification · Ozone
10% energy rule: only ~10% of energy transfers from one trophic level to the next; 90% lost as heat.
Biomagnification: non-biodegradable chemicals (DDT) increase in concentration at higher trophic levels.
Ozone layer (stratosphere) absorbs harmful UV radiation. CFCs cause ozone depletion → ozone hole.
3 R's: Reduce, Reuse, Recycle – sustainable waste management.
📘 Learnify Academy — CBSE Tuition in Bahrain
Experienced teachers · Small groups · Weekly assessments · Exam-oriented preparation
Enroll for CBSE Tuition →Quick Revision Tips & Exam Strategy
Last-minute pointers to maximise your score
📋
Formulas Cheat Sheet
Mirror: \(1/f=1/v+1/u\), Lens: \(1/f=1/v-1/u\), Ohm's \(V=IR\), Power \(P=VI\).
⚡
Attempt Order
MCQs first → 2-mark → 3-mark → 5-mark with diagrams.
✍️
Balance Equations
Always include state symbols. Double-check coefficients.
🖊️
Label Diagrams
Human eye, nephron, ray diagrams – labels earn full marks.
🔍
Mirror vs Lens
Mirror: \(m=-v/u\); Lens: \(m=v/u\). Formula signs differ.
🎯
High-Yield Topics
Chemical equations, Life processes, Electricity numericals, Reflection, Heredity.