CBSE Grade 8 Science Exam Survival Guide

Window: Annual Exam | Units: Physics, Chemistry, Biology

Must-do topics (with how-to + examples)

• Crop Production & Management → Tools, irrigation, storage, protection.
• Microorganisms → Useful (antibiotics, fermentation), harmful (diseases).
• Materials: Metals & Non-metals → Properties, uses, reactions (O₂, acids, bases).
  Ex: Zn + H₂SO₄ → ZnSO₄ + H₂↑.
• Coal & Petroleum → Natural resources, refining, conservation.
• Combustion & Flame → Types, zones of flame, precautions.
• Cell Structure → Organelles (nucleus, mitochondria, chloroplast).
• Reproduction in Animals → Asexual (binary fission, budding), Sexual (fertilisation, oviparous vs viviparous).
• Reaching the Age of Adolescence → Hormones, changes, health.
• Force & Pressure → Contact/non-contact forces; pressure=F/A.
• Friction → Uses, disadvantages, methods to reduce.
• Sound → Production, vibration, propagation, human ear.
• Light → Laws of reflection, human eye, defects & corrections.
• Electric Current → Symbols, heating/chemical effects.
• Pollution of Air & Water → Causes, prevention.

Top traps (avoid)

• Forgetting to balance chemical equations.
• Bio diagrams unlabeled.
• Physics numericals: missing units.
• Mixing puberty/adolescence terms.

Time split

Bio 35% | Chem 35% | Physics 30%
Do diagrams early, numericals mid, definitions last.

Last-48h checklist

• Redraw 8 diagrams (cell, reproductive system, eye, ear, circuit, flame, chloroplast, nephron).
• 20 flashcards (hormones, metals vs non-metals, microorganisms).
• 1 past paper timed.

Quick facts / formulas

• Photosynthesis: CO₂+H₂O → Glucose+O₂.
• Pressure = Force/Area (N/m² = Pascal).
• Speed of sound in air ≈ 340 m/s.
• Laws of reflection: ∠i=∠r.

Speed tactics

• Start answers: define → explain → example/diagram.
• Use arrows in diagrams (flow of current, direction of force).
• Box final numerical with unit.

Exam-day mini-plan

• Write all diagrams big & neat early.
• Do numericals next; definitions last.
• Keep 10 min for labels/units.