The team at periodicvideos has created a TED-Ed Lesson for every element of the periodic table. This one is about the first "useful" metal on the periodic table. It famously burns very brightly when exposed to flame. It's magnesium.
As you can see in the Periodic Video “Carbon Dioxide (Part II),” magnesium can burn in CO2 in a very exothermic reaction. That reaction produces a white solid (magnesium oxide) and a black solid (elemental carbon).