--EDIT-- 1. Photons to radioactive ( makes room for posssible indestructable metal) 2. Fuse and Fuse Powder to explosives. 3. Cold flame to gases. 4. Portal in and portal out to special. 5. Insulation to electronics or solids 6. Vac and Air to gases
-- Popular opinion says that fire stays in explosives although it isnt one. People like it handy to make things go boom. Powder toy is supposed to be fun not realistic( all the time, anyway).