An arson investigator is called to a suspicious fire that destroyed a house. The arson investigator collects a sample of debris, which was found at the base of the structure, containing some accelerant used to start the fire. Once the investigator goes back to the lab and tests the sample, a purple flame is emitted from the sample. What metal was part of the accelerant used to burn the house?

Question

Vocaloid · Answer

Looking at flame test colors, potassium seems to be a major possibility. Some less common metals that burn purple (or purple-ish) are rubidium and cesium. https://i0.wp.com/www.compoundchem.com/wp-content/uploads/2014/02/Metal-Ion-Flame-Tests.png?fit=580%2C407&ssl=1