Nitro-9
Nitro-9 was a powerful explosive created by Ace in school, which she blew up the science building with. Ace mixed it herself and put it inside deodorant cans.
Nitro-9 was a variant of Nitroglycerin. A variant of Nitro-9 was Nitro-9a, which was half the size and half as powerful. (PROSE: Timewyrm: Exodus) Another variant of Nitro-9 was Neo-Nitro, which resembled boiled sweets and was activated using saliva. (PROSE: Shadowmind) Ace also created Nitro-9 smart bombs, which could fly and take verbal commands. (PROSE: Blood Heat)
Though the Seventh Doctor told Ace not to carry it, she continued to do so and used it to destroy a Renegade Dalek (TV: Remembrance of the Daleks), a Cyber-shuttle (TV: Silver Nemesis), in a failed attempt to kill Fifi (TV: The Happiness Patrol), and to open the entrance to King Arthur's spaceship. (TV: Battlefield)