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Explosives: classification and requirements

Short answer

An explosive is a substance that undergoes rapid exothermic decomposition releasing hot gases, causing pressure rise. Explosives are classified as low (black powder, smokeless powder) that deflagrate, and high (primary: lead azide; secondary: TNT, RDX) that detonate; plastic explosives (C-4) are mouldable high explosives. Good explosives are stable, safe, easily initiated, have high brisance, produce large gas volume, and are cheap.

What is an explosive? Classify explosives with examples. What is the requirement of good explosives?

Explosive

An explosive is a substance (or mixture) that, on heating, shock or friction, undergoes a very fast, highly exothermic decomposition that releases a large volume of hot gases, causing a sudden rise in pressure with heat, light and sound.

Classification

Explosives
 ├── Low explosives   (deflagrate)  black powder, smokeless powder
 ├── High explosives  (detonate)
 │     ├── Primary    lead azide, mercury fulminate
 │     └── Secondary  TNT, RDX, PETN, picric acid, dynamite
 └── Plastic explosives  C-4, Semtex
  • Low explosives: burn quickly, produce propelling effect; used as propellants.
  • High explosives: detonate with shattering effect; primary ones are initiators, secondary ones are the main charge.
  • Plastic explosives: moulded high explosives.

Requirements of a good explosive

  1. Stable during storage, without decomposing over time.
  2. Safe to handle: not too sensitive to shock, friction or heat.
  3. Easily exploded by a detonator or proper initiation.
  4. High velocity of detonation and brisance (shattering power).
  5. Large volume of gas released per unit mass, with high heat of explosion.
  6. Gives little smoke and no poisonous fumes (for use in mines).
  7. Cheap, easy to make from available raw materials, and non-hygroscopic.

✓ Answer checked by Claude Opus 5.5 (high effort)

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