Achemical that causes a sudden, almost instantaneous release of pressure, gas, and heat when subjected to sudden shock, pressure, or high temperatures best describes which type of dot hazardous materials classification?

The correct answer is class I explosives.

Explanation:

An explosive refers to a chemical, which leads to a sudden, almost immediate discharge of gas, pressure, and heat when exposed to sudden pressure, shock, or high temperature. These are unstable substances and are primarily of two kinds.  

The type one comprises of substances possessing the tendency of undergoing supersonic reactions, like TNT and nitroglycerin. The other kind comprises substances, which burn briskly, however, at a subsonic rate. The examples are rocket propellants, gunpowder, and fireworks.  

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.