<P> Sensitivity is an important consideration in selecting an explosive for a particular purpose . The explosive in an armor - piercing projectile must be relatively insensitive, or the shock of impact would cause it to detonate before it penetrated to the point desired . The explosive lenses around nuclear charges are also designed to be highly insensitive, to minimize the risk of accidental detonation . </P> <P> The index of the capacity of an explosive to be initiated into detonation in a sustained manner . It is defined by the power of the detonator which is certain to prime the explosive to a sustained and continuous detonation . Reference is made to the Sellier - Bellot scale that consists of a series of 10 detonators, from n . 1 to n . 10, each of which corresponds to an increasing charge weight . In practice, most of the explosives on the market today are sensitive to an n . 8 detonator, where the charge corresponds to 2 grams of mercury fulminate . </P> <P> The velocity with which the reaction process propagates in the mass of the explosive . Most commercial mining explosives have detonation velocities ranging from 1800 m / s to 8000 m / s . Today, velocity of detonation can be measured with accuracy . Together with density it is an important element influencing the yield of the energy transmitted for both atmospheric over-pressure and ground acceleration . By definition, a "low explosive," such as black powder, or smokeless gunpowder has a burn rate of 171--631 m / s . In contrast, a "high explosive," whether a primary, such as detonating cord, or a secondary, such as TNT or C - 4 has a significantly higher burn rate . </P> <P> Stability is the ability of an explosive to be stored without deterioration . </P>

Tnt is an example of a high explosive