Changes Around Us

Melting ice, rusting gate, burning candle — what's reversible and what's not? 🔁

📖 Concepts

1Changes are everywhere→2Reversible vs irreversible→3Physical changes→4Chemical changes→5Rusting — a common chemical change→6Expansion and contraction→7Fast vs slow changes→8Useful changes we engineer→

🎯 Practice questions

The tier ladder: 🌱basic warms you up, ⚡regular is exam-paced, 🔥hard twists the same ideas. The 🏆olympiad tier matches the “Achievers” section of the real exam.