I'm working on a story involving vampires, set during various parts of the sort-of-AU-20th century. The scene in question is in 1925, and it's involving a vampire's murder. The death was due to sunlight exposure (as one might expect for a vampire), but I had what might be an insane idea.
In theory, there's some element of sunlight which makes it toxic to vampires. What elements make up light, I guess is what I'm asking? Because genetically, then, vampires could in theory be bred with resistance to that element, or perhaps the element could be solidified or liquified to use as an anti-vamp weapon.
This is slightly AU, so I don't mind a little fact-bending, but I'd like it not to be completely outlandish. Could someone enlighten me, or at least give me suggestions on what to search?
ETA: I really appreciate the quick responses - can you tell I didn't pay attention in chemistry? << Light wavelengths or energy frequencies might work for my purposes, though; thanks!