Natural rubber becomes soft at high temperatures and brittle at low temperatures. To improve it, raw rubber is heated with which element in the process called vulcanisation?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Sulphur
In vulcanisation, raw rubber is heated with sulphur and suitable additives. Sulphur forms cross-links between the rubber chains, making the rubber stiffer, tougher and useful over a wider range of temperatures, as in tyres.