CBSE Grade 3-12 Exam Survival Guide: Science — 80/20 by stage (high-yield + classic misconceptions)

Grades 3–5

• Human Body systems; Plant structure; Simple machines; States of matter; Water cycle
  Struggles: label-without-function answers; cycle steps missed. Work on: “define→function→diagram” routine; arrowed flowcharts.

Grades 6–8

• Electricity basics (circuits, series/parallel); Heat & Light; Force/Pressure; Cell & Reproduction; Microorganisms; Metals/Non-metals
  Struggles: current vs voltage, series/parallel predictions; image formation rules; balancing equations. Work on: predict→test labs with low-stakes circuits; mirror/lens ray-kits; red-pen coefficient check. 

Grades 9–10

• Physics: Electricity (Ohm/Kirchhoff/Power), Magnetism, Light (lens/mirror), Human Eye.
  Struggles: sign conventions; series/parallel blends. Work on: sign-table next to every ray/numerical; reduce-the-circuit first. 
• Chemistry: Reactions & types; Acids/Bases/Salts (pH & key salts); Metals/Non-metals; Carbon & compounds; Periodic trends.
  Struggles: partial balancing; rate/order vs molecularity. Work on: “state symbols + atoms + charge” triple-check; rate-law units cue.
• Biology: Life processes; Reproduction; Heredity & evolution; Environment.
  Struggles: text-only answers, unlabeled diagrams. Work on: diagram-first with labels; Mendel ratio mini-grids.

Grades 11–12

• Physics: Electrostatics/Current/Magnetism; EMI & AC; Optics; Modern; Semiconductors.
  Struggles: unit discipline, vector sign sense. Work on G–T–F–U steps (Given→To-find→Formula→Units).
• Chemistry: Electrochem, Kinetics, Thermodynamics, Solutions, Coordination; Org: GOC→Carbonyls→Amines.
  Struggles: Nernst log slips; mechanism conditions. Work on: 0.0591/n “at 25 °C” sticky; reagent-to-product flashcards.

Biology: Genetics (linkage/HW), Molecular, Biotech, Ecology.
Struggles: pedigree + stats; HW assumptions. Work on: pedigree decision tree; χ² table habit.