The bright-red color of highway safety flares comes from strontium ions in salts such as Sr(NO3)2 and SrCO3. Burning a flare...

The bright-red color of highway safety flares comes from strontium ions in salts such as Sr(NO₃)₂ and SrCO₃. Burning a flare produces strontium ions in excited states, which then emit red photons at 606 nm and several wavelengths between 636 and 688 nm. Calculate the energy (in Joules per mole) of the 652 nm emission.