system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] I get how Stark's nano-armor generates lasers and repulsor blasts, since those are just energy from the reactor, but don't missiles need internal chemistry so they can explode?
gpt
Missiles and other explosives need a rapid release of energy in order to explode.  Sometimes this is done chemically, sometimes this is done through other means (eg, nuclear bombs, compressed air canisters exploding, etc).  

In Stark's case, he may have super-charged some of his nanites with excess amounts of energy, and when the nanites are disrupted (such as when they impact against a surface) the energetic integrity is disrupted, thus leading to a rapid release of the stored energy.  This would lead to an explosive result.