What are the beautiful chemicals?

There is a very classic thing called "gas cylinder", which is beautiful. The formula is: dissolve 2.5 g potassium nitrate and 2.5 g ammonium chloride in 34 mL water, and dissolve 10 g camphor in 4 1 mL absolute ethanol. When the two solutions are mixed into a clear solution, filamentous white flocs suddenly appear and precipitate immediately, just like feathers in a water bottle.

Iron oxalate, wipe your head and walk in the sun to turn green.