What is the defining characteristic of high explosives?

The defining characteristic of high explosives is that they are designed to be detonated by shock. High explosives, such as TNT or RDX, are materials that can undergo a rapid and violent chemical reaction when subjected to a shockwave, such as that produced by an impact or a detonator. This detonation results in a very quick release of energy and produces a powerful explosion.

This characteristic is essential for their use in applications such as demolition, military ordnance, and other fields where a quick and powerful reaction is necessary. The ability to be detonated by shock allows for precise control in various applications, distinguishing high explosives from low explosives, which typically require a slower burning process and might not generate the same immediate explosive effects.

In contrast, the other options do not accurately reflect the nature of high explosives. For instance, low detonation velocity does not apply to high explosives, as they often have very high detonation velocities. High explosives do not require slow ignition; this is characteristic of low explosives. Lastly, while high explosives can produce harmful gases as a byproduct of their detonation, this is not a defining characteristic of their explosive nature.