NCERT Solutions for Curiosity Chapter 4 The World of Metals and Non-metals
Updated on 2026-09-05
About this chapter
Metals are generally lustrous (they show metallic lustre), hard , malleable (can be beaten into thin sheets), ductile (can be drawn into wires) and sonorous (give a ringing sound). Copper, aluminium, iron, gold and silver are metals. There are exceptions to every rule — sodium and potassium are so soft they can be cut with a knife , and mercury is a liquid at room temperature. Metals are good conductors of heat and electricity . That is why cooking vessels are metal while their handles are wood, and why an electrician's screwdriver has a plastic grip and rubber gloves. Non-metals such as coal (carbon), sulfur and phosphorus are dull, soft, brittle, non-ductile, non-sonorous and poor conductors of heat and electricity. Metal oxides are basic — burning magnesium gives magnesium oxide, whose
- Yashwant and Anandi visit the ironsmith
- Malleability
- The impact of iron on the progress of civilisation of India
- Sections 4.1.2 Ductility and 4.1.3 Sonority
- Sonority
- Conduction of heat
- Conduction of electricity
- Effect of Air and Water on Metals: Iron
- — Corrosion
- Effect of Air and Water on Other Metals
Exercises
- Yashwant and Anandi visit the ironsmith — In-text Questions Page 41 & 42
- Activity 4.1: Let us explore — Malleability Page 42
- In-text Questions — Malleability Page 43
- The impact of iron on the progress of civilisation of India — Holistic Lens Page 44
- Sections 4.1.2 Ductility and 4.1.3 Sonority — In-text Questions Page 44 & 45
- Activity 4.2: Let us investigate — Sonority Page 45
- In-text Questions — Conduction of heat Page 46
- Activity 4.3: Let us investigate — Conduction of heat Page 46 & 47
- In-text Questions — Conduction of electricity Page 47
- Activity 4.4: Let us design and create — Conduction of electricity Page 47 & 48
- In-text Questions — Effect of Air and Water on Metals: Iron Page 48
- Activity 4.5: Let us experiment — Effect of Air and Water on Metals: Iron Page 49 & 50
- In-text Questions — — Corrosion Page 50
- Activity 4.6: Let us investigate (demonstration activity) — Effect of Air and Water on Other Metals Page 51
- In-text Questions — — Sodium Page 52
- Activity 4.7: Let us experiment (demonstration activity) — Substances that Behave Differently from Metals in Air and Water Page 52 & 53
- Activity 4.8: Let us explore — Substances that Behave Differently from Metals in Air and Water Page 53
- In-text Questions — Are Non-metals Essential in Everyday Life? Page 54
- End-of-chapter exercise — Let Us Enhance Our Learning Page 55 & 56
- Projects and further exploration — Exploratory Projects Page 56